Merging upstream version 1.66.0+dfsg1.

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

7 files changed, 161 insertions, 69 deletions

diff --git a/src/tools/rust-analyzer/crates/mbe/Cargo.toml b/src/tools/rust-analyzer/crates/mbe/Cargo.toml
index 5ff3448a1..13cd89010 100644
--- a/src/tools/rust-analyzer/crates/mbe/Cargo.toml
+++ b/src/tools/rust-analyzer/crates/mbe/Cargo.toml
@@ -12,7 +12,7 @@ doctest = false
 [dependencies]
 cov-mark = "2.0.0-pre.1"
 rustc-hash = "1.1.0"
-smallvec = "1.9.0"
+smallvec = "1.10.0"
 tracing = "0.1.35"
 
 syntax = { path = "../syntax", version = "0.0.0" }
diff --git a/src/tools/rust-analyzer/crates/mbe/src/benchmark.rs b/src/tools/rust-analyzer/crates/mbe/src/benchmark.rs
index ac691578d..9c92bae6a 100644
--- a/src/tools/rust-analyzer/crates/mbe/src/benchmark.rs
+++ b/src/tools/rust-analyzer/crates/mbe/src/benchmark.rs
@@ -8,7 +8,7 @@ use syntax::{
 use test_utils::{bench, bench_fixture, skip_slow_tests};
 
 use crate::{
-    parser::{Op, RepeatKind, Separator},
+    parser::{MetaVarKind, Op, RepeatKind, Separator},
     syntax_node_to_token_tree, DeclarativeMacro,
 };
 
@@ -111,35 +111,35 @@ fn invocation_fixtures(rules: &FxHashMap<String, DeclarativeMacro>) -> Vec<(Stri
 
     fn collect_from_op(op: &Op, parent: &mut tt::Subtree, seed: &mut usize) {
         return match op {
-            Op::Var { kind, .. } => match kind.as_ref().map(|it| it.as_str()) {
-                Some("ident") => parent.token_trees.push(make_ident("foo")),
-                Some("ty") => parent.token_trees.push(make_ident("Foo")),
-                Some("tt") => parent.token_trees.push(make_ident("foo")),
-                Some("vis") => parent.token_trees.push(make_ident("pub")),
-                Some("pat") => parent.token_trees.push(make_ident("foo")),
-                Some("path") => parent.token_trees.push(make_ident("foo")),
-                Some("literal") => parent.token_trees.push(make_literal("1")),
-                Some("expr") => parent.token_trees.push(make_ident("foo")),
-                Some("lifetime") => {
+            Op::Var { kind, .. } => match kind.as_ref() {
+                Some(MetaVarKind::Ident) => parent.token_trees.push(make_ident("foo")),
+                Some(MetaVarKind::Ty) => parent.token_trees.push(make_ident("Foo")),
+                Some(MetaVarKind::Tt) => parent.token_trees.push(make_ident("foo")),
+                Some(MetaVarKind::Vis) => parent.token_trees.push(make_ident("pub")),
+                Some(MetaVarKind::Pat) => parent.token_trees.push(make_ident("foo")),
+                Some(MetaVarKind::Path) => parent.token_trees.push(make_ident("foo")),
+                Some(MetaVarKind::Literal) => parent.token_trees.push(make_literal("1")),
+                Some(MetaVarKind::Expr) => parent.token_trees.push(make_ident("foo")),
+                Some(MetaVarKind::Lifetime) => {
                     parent.token_trees.push(make_punct('\''));
                     parent.token_trees.push(make_ident("a"));
                 }
-                Some("block") => {
+                Some(MetaVarKind::Block) => {
                     parent.token_trees.push(make_subtree(tt::DelimiterKind::Brace, None))
                 }
-                Some("item") => {
+                Some(MetaVarKind::Item) => {
                     parent.token_trees.push(make_ident("fn"));
                     parent.token_trees.push(make_ident("foo"));
                     parent.token_trees.push(make_subtree(tt::DelimiterKind::Parenthesis, None));
                     parent.token_trees.push(make_subtree(tt::DelimiterKind::Brace, None));
                 }
-                Some("meta") => {
+                Some(MetaVarKind::Meta) => {
                     parent.token_trees.push(make_ident("foo"));
                     parent.token_trees.push(make_subtree(tt::DelimiterKind::Parenthesis, None));
                 }
 
                 None => (),
-                Some(kind) => panic!("Unhandled kind {}", kind),
+                Some(kind) => panic!("Unhandled kind {:?}", kind),
             },
             Op::Leaf(leaf) => parent.token_trees.push(leaf.clone().into()),
             Op::Repeat { tokens, kind, separator } => {
diff --git a/src/tools/rust-analyzer/crates/mbe/src/expander.rs b/src/tools/rust-analyzer/crates/mbe/src/expander.rs
index 1e1bfa550..100ec6bfb 100644
--- a/src/tools/rust-analyzer/crates/mbe/src/expander.rs
+++ b/src/tools/rust-analyzer/crates/mbe/src/expander.rs
@@ -8,7 +8,7 @@ mod transcriber;
 use rustc_hash::FxHashMap;
 use syntax::SmolStr;
 
-use crate::{ExpandError, ExpandResult};
+use crate::{parser::MetaVarKind, ExpandError, ExpandResult};
 
 pub(crate) fn expand_rules(
     rules: &[crate::Rule],
@@ -104,6 +104,7 @@ enum Binding {
     Fragment(Fragment),
     Nested(Vec<Binding>),
     Empty,
+    Missing(MetaVarKind),
 }
 
 #[derive(Debug, Clone, PartialEq, Eq)]
diff --git a/src/tools/rust-analyzer/crates/mbe/src/expander/matcher.rs b/src/tools/rust-analyzer/crates/mbe/src/expander/matcher.rs
index c1aa14d6b..3f656df25 100644
--- a/src/tools/rust-analyzer/crates/mbe/src/expander/matcher.rs
+++ b/src/tools/rust-analyzer/crates/mbe/src/expander/matcher.rs
@@ -66,7 +66,7 @@ use syntax::SmolStr;
 
 use crate::{
     expander::{Binding, Bindings, ExpandResult, Fragment},
-    parser::{Op, RepeatKind, Separator},
+    parser::{MetaVarKind, Op, RepeatKind, Separator},
     tt_iter::TtIter,
     ExpandError, MetaTemplate,
 };
@@ -119,6 +119,7 @@ pub(super) fn match_(pattern: &MetaTemplate, input: &tt::Subtree) -> Match {
             .map(|it| match it {
                 Binding::Fragment(_) => 1,
                 Binding::Empty => 1,
+                Binding::Missing(_) => 1,
                 Binding::Nested(it) => count(it.iter()),
             })
             .sum()
@@ -130,6 +131,7 @@ enum BindingKind {
     Empty(SmolStr),
     Optional(SmolStr),
     Fragment(SmolStr, Fragment),
+    Missing(SmolStr, MetaVarKind),
     Nested(usize, usize),
 }
 
@@ -190,6 +192,10 @@ impl BindingsBuilder {
             .push(LinkNode::Node(Rc::new(BindingKind::Fragment(var.clone(), fragment))));
     }
 
+    fn push_missing(&mut self, idx: &mut BindingsIdx, var: &SmolStr, kind: MetaVarKind) {
+        self.nodes[idx.0].push(LinkNode::Node(Rc::new(BindingKind::Missing(var.clone(), kind))));
+    }
+
     fn push_nested(&mut self, parent: &mut BindingsIdx, child: &BindingsIdx) {
         let BindingsIdx(idx, nidx) = self.copy(child);
         self.nodes[parent.0].push(LinkNode::Node(Rc::new(BindingKind::Nested(idx, nidx))));
@@ -203,17 +209,16 @@ impl BindingsBuilder {
     }
 
     fn build(self, idx: &BindingsIdx) -> Bindings {
-        let mut bindings = Bindings::default();
-        self.build_inner(&mut bindings, &self.nodes[idx.0]);
-        bindings
+        self.build_inner(&self.nodes[idx.0])
     }
 
-    fn build_inner(&self, bindings: &mut Bindings, link_nodes: &[LinkNode<Rc<BindingKind>>]) {
+    fn build_inner(&self, link_nodes: &[LinkNode<Rc<BindingKind>>]) -> Bindings {
+        let mut bindings = Bindings::default();
         let mut nodes = Vec::new();
         self.collect_nodes(link_nodes, &mut nodes);
 
         for cmd in nodes {
-            match &**cmd {
+            match cmd {
                 BindingKind::Empty(name) => {
                     bindings.push_empty(name);
                 }
@@ -223,6 +228,9 @@ impl BindingsBuilder {
                 BindingKind::Fragment(name, fragment) => {
                     bindings.inner.insert(name.clone(), Binding::Fragment(fragment.clone()));
                 }
+                BindingKind::Missing(name, kind) => {
+                    bindings.inner.insert(name.clone(), Binding::Missing(*kind));
+                }
                 BindingKind::Nested(idx, nested_idx) => {
                     let mut nested_nodes = Vec::new();
                     self.collect_nested(*idx, *nested_idx, &mut nested_nodes);
@@ -246,13 +254,15 @@ impl BindingsBuilder {
                 }
             }
         }
+
+        bindings
     }
 
     fn collect_nested_ref<'a>(
         &'a self,
         id: usize,
         len: usize,
-        nested_refs: &mut Vec<&'a Vec<LinkNode<Rc<BindingKind>>>>,
+        nested_refs: &mut Vec<&'a [LinkNode<Rc<BindingKind>>]>,
     ) {
         self.nested[id].iter().take(len).for_each(|it| match it {
             LinkNode::Node(id) => nested_refs.push(&self.nodes[*id]),
@@ -262,26 +272,16 @@ impl BindingsBuilder {
 
     fn collect_nested(&self, idx: usize, nested_idx: usize, nested: &mut Vec<Bindings>) {
         let last = &self.nodes[idx];
-        let mut nested_refs = Vec::new();
+        let mut nested_refs: Vec<&[_]> = Vec::new();
         self.nested[nested_idx].iter().for_each(|it| match *it {
             LinkNode::Node(idx) => nested_refs.push(&self.nodes[idx]),
             LinkNode::Parent { idx, len } => self.collect_nested_ref(idx, len, &mut nested_refs),
         });
         nested_refs.push(last);
-
-        nested_refs.into_iter().for_each(|iter| {
-            let mut child_bindings = Bindings::default();
-            self.build_inner(&mut child_bindings, iter);
-            nested.push(child_bindings)
-        })
+        nested.extend(nested_refs.into_iter().map(|iter| self.build_inner(iter)));
     }
 
-    fn collect_nodes_ref<'a>(
-        &'a self,
-        id: usize,
-        len: usize,
-        nodes: &mut Vec<&'a Rc<BindingKind>>,
-    ) {
+    fn collect_nodes_ref<'a>(&'a self, id: usize, len: usize, nodes: &mut Vec<&'a BindingKind>) {
         self.nodes[id].iter().take(len).for_each(|it| match it {
             LinkNode::Node(it) => nodes.push(it),
             LinkNode::Parent { idx, len } => self.collect_nodes_ref(*idx, *len, nodes),
@@ -291,7 +291,7 @@ impl BindingsBuilder {
     fn collect_nodes<'a>(
         &'a self,
         link_nodes: &'a [LinkNode<Rc<BindingKind>>],
-        nodes: &mut Vec<&'a Rc<BindingKind>>,
+        nodes: &mut Vec<&'a BindingKind>,
     ) {
         link_nodes.iter().for_each(|it| match it {
             LinkNode::Node(it) => nodes.push(it),
@@ -386,10 +386,10 @@ fn match_loop_inner<'t>(
         let op = match item.dot.peek() {
             None => {
                 // We are at or past the end of the matcher of `item`.
-                if item.up.is_some() {
+                if let Some(up) = &item.up {
                     if item.sep_parsed.is_none() {
                         // Get the `up` matcher
-                        let mut new_pos = *item.up.clone().unwrap();
+                        let mut new_pos = (**up).clone();
                         new_pos.bindings = bindings_builder.copy(&new_pos.bindings);
                         // Add matches from this repetition to the `matches` of `up`
                         bindings_builder.push_nested(&mut new_pos.bindings, &item.bindings);
@@ -402,7 +402,7 @@ fn match_loop_inner<'t>(
 
                     // Check if we need a separator.
                     // We check the separator one by one
-                    let sep_idx = *item.sep_parsed.as_ref().unwrap_or(&0);
+                    let sep_idx = item.sep_parsed.unwrap_or(0);
                     let sep_len = item.sep.as_ref().map_or(0, Separator::tt_count);
                     if item.sep.is_some() && sep_idx != sep_len {
                         let sep = item.sep.as_ref().unwrap();
@@ -467,9 +467,9 @@ fn match_loop_inner<'t>(
                 }
             }
             OpDelimited::Op(Op::Var { kind, name, .. }) => {
-                if let Some(kind) = kind {
+                if let &Some(kind) = kind {
                     let mut fork = src.clone();
-                    let match_res = match_meta_var(kind.as_str(), &mut fork);
+                    let match_res = match_meta_var(kind, &mut fork);
                     match match_res.err {
                         None => {
                             // Some meta variables are optional (e.g. vis)
@@ -484,8 +484,15 @@ fn match_loop_inner<'t>(
                         }
                         Some(err) => {
                             res.add_err(err);
-                            if let Some(fragment) = match_res.value {
-                                bindings_builder.push_fragment(&mut item.bindings, name, fragment);
+                            match match_res.value {
+                                Some(fragment) => bindings_builder.push_fragment(
+                                    &mut item.bindings,
+                                    name,
+                                    fragment,
+                                ),
+                                None => {
+                                    bindings_builder.push_missing(&mut item.bindings, name, kind)
+                                }
                             }
                             item.is_error = true;
                             error_items.push(item);
@@ -677,20 +684,20 @@ fn match_leaf(lhs: &tt::Leaf, src: &mut TtIter<'_>) -> Result<(), ExpandError> {
     }
 }
 
-fn match_meta_var(kind: &str, input: &mut TtIter<'_>) -> ExpandResult<Option<Fragment>> {
+fn match_meta_var(kind: MetaVarKind, input: &mut TtIter<'_>) -> ExpandResult<Option<Fragment>> {
     let fragment = match kind {
-        "path" => parser::PrefixEntryPoint::Path,
-        "ty" => parser::PrefixEntryPoint::Ty,
+        MetaVarKind::Path => parser::PrefixEntryPoint::Path,
+        MetaVarKind::Ty => parser::PrefixEntryPoint::Ty,
         // FIXME: These two should actually behave differently depending on the edition.
         //
         // https://doc.rust-lang.org/edition-guide/rust-2021/or-patterns-macro-rules.html
-        "pat" | "pat_param" => parser::PrefixEntryPoint::Pat,
-        "stmt" => parser::PrefixEntryPoint::Stmt,
-        "block" => parser::PrefixEntryPoint::Block,
-        "meta" => parser::PrefixEntryPoint::MetaItem,
-        "item" => parser::PrefixEntryPoint::Item,
-        "vis" => parser::PrefixEntryPoint::Vis,
-        "expr" => {
+        MetaVarKind::Pat | MetaVarKind::PatParam => parser::PrefixEntryPoint::Pat,
+        MetaVarKind::Stmt => parser::PrefixEntryPoint::Stmt,
+        MetaVarKind::Block => parser::PrefixEntryPoint::Block,
+        MetaVarKind::Meta => parser::PrefixEntryPoint::MetaItem,
+        MetaVarKind::Item => parser::PrefixEntryPoint::Item,
+        MetaVarKind::Vis => parser::PrefixEntryPoint::Vis,
+        MetaVarKind::Expr => {
             // `expr` should not match underscores.
             // HACK: Macro expansion should not be done using "rollback and try another alternative".
             // rustc [explicitly checks the next token][0].
@@ -707,17 +714,17 @@ fn match_meta_var(kind: &str, input: &mut TtIter<'_>) -> ExpandResult<Option<Fra
         }
         _ => {
             let tt_result = match kind {
-                "ident" => input
+                MetaVarKind::Ident => input
                     .expect_ident()
                     .map(|ident| tt::Leaf::from(ident.clone()).into())
                     .map_err(|()| ExpandError::binding_error("expected ident")),
-                "tt" => input
+                MetaVarKind::Tt => input
                     .expect_tt()
                     .map_err(|()| ExpandError::binding_error("expected token tree")),
-                "lifetime" => input
+                MetaVarKind::Lifetime => input
                     .expect_lifetime()
                     .map_err(|()| ExpandError::binding_error("expected lifetime")),
-                "literal" => {
+                MetaVarKind::Literal => {
                     let neg = input.eat_char('-');
                     input
                         .expect_literal()
diff --git a/src/tools/rust-analyzer/crates/mbe/src/expander/transcriber.rs b/src/tools/rust-analyzer/crates/mbe/src/expander/transcriber.rs
index 7bcc84740..cbb59ab8e 100644
--- a/src/tools/rust-analyzer/crates/mbe/src/expander/transcriber.rs
+++ b/src/tools/rust-analyzer/crates/mbe/src/expander/transcriber.rs
@@ -6,7 +6,7 @@ use tt::{Delimiter, Subtree};
 
 use crate::{
     expander::{Binding, Bindings, Fragment},
-    parser::{Op, RepeatKind, Separator},
+    parser::{MetaVarKind, Op, RepeatKind, Separator},
     ExpandError, ExpandResult, MetaTemplate,
 };
 
@@ -15,7 +15,7 @@ impl Bindings {
         self.inner.contains_key(name)
     }
 
-    fn get(&self, name: &str, nesting: &mut [NestingState]) -> Result<&Fragment, ExpandError> {
+    fn get(&self, name: &str, nesting: &mut [NestingState]) -> Result<Fragment, ExpandError> {
         macro_rules! binding_err {
             ($($arg:tt)*) => { ExpandError::binding_error(format!($($arg)*)) };
         }
@@ -26,6 +26,7 @@ impl Bindings {
             nesting_state.hit = true;
             b = match b {
                 Binding::Fragment(_) => break,
+                Binding::Missing(_) => break,
                 Binding::Nested(bs) => bs.get(nesting_state.idx).ok_or_else(|| {
                     nesting_state.at_end = true;
                     binding_err!("could not find nested binding `{name}`")
@@ -37,7 +38,55 @@ impl Bindings {
             };
         }
         match b {
-            Binding::Fragment(it) => Ok(it),
+            Binding::Fragment(it) => Ok(it.clone()),
+            // emit some reasonable default expansion for missing bindings,
+            // this gives better recovery than emitting the `$fragment-name` verbatim
+            Binding::Missing(it) => Ok(match it {
+                MetaVarKind::Stmt => {
+                    Fragment::Tokens(tt::TokenTree::Leaf(tt::Leaf::Punct(tt::Punct {
+                        id: tt::TokenId::unspecified(),
+                        char: ';',
+                        spacing: tt::Spacing::Alone,
+                    })))
+                }
+                MetaVarKind::Block => Fragment::Tokens(tt::TokenTree::Subtree(tt::Subtree {
+                    delimiter: Some(tt::Delimiter {
+                        id: tt::TokenId::unspecified(),
+                        kind: tt::DelimiterKind::Brace,
+                    }),
+                    token_trees: vec![],
+                })),
+                // FIXME: Meta and Item should get proper defaults
+                MetaVarKind::Meta | MetaVarKind::Item | MetaVarKind::Tt | MetaVarKind::Vis => {
+                    Fragment::Tokens(tt::TokenTree::Subtree(tt::Subtree {
+                        delimiter: None,
+                        token_trees: vec![],
+                    }))
+                }
+                MetaVarKind::Path
+                | MetaVarKind::Ty
+                | MetaVarKind::Pat
+                | MetaVarKind::PatParam
+                | MetaVarKind::Expr
+                | MetaVarKind::Ident => {
+                    Fragment::Tokens(tt::TokenTree::Leaf(tt::Leaf::Ident(tt::Ident {
+                        text: SmolStr::new_inline("missing"),
+                        id: tt::TokenId::unspecified(),
+                    })))
+                }
+                MetaVarKind::Lifetime => {
+                    Fragment::Tokens(tt::TokenTree::Leaf(tt::Leaf::Ident(tt::Ident {
+                        text: SmolStr::new_inline("'missing"),
+                        id: tt::TokenId::unspecified(),
+                    })))
+                }
+                MetaVarKind::Literal => {
+                    Fragment::Tokens(tt::TokenTree::Leaf(tt::Leaf::Ident(tt::Ident {
+                        text: SmolStr::new_inline("\"missing\""),
+                        id: tt::TokenId::unspecified(),
+                    })))
+                }
+            }),
             Binding::Nested(_) => {
                 Err(binding_err!("expected simple binding, found nested binding `{name}`"))
             }
@@ -157,7 +206,7 @@ fn expand_var(ctx: &mut ExpandCtx<'_>, v: &SmolStr, id: tt::TokenId) -> ExpandRe
     } else {
         ctx.bindings.get(v, &mut ctx.nesting).map_or_else(
             |e| ExpandResult { value: Fragment::Tokens(tt::TokenTree::empty()), err: Some(e) },
-            |b| ExpandResult::ok(b.clone()),
+            |it| ExpandResult::ok(it),
         )
     }
 }
diff --git a/src/tools/rust-analyzer/crates/mbe/src/lib.rs b/src/tools/rust-analyzer/crates/mbe/src/lib.rs
index 79da84f4a..c4f0fa20d 100644
--- a/src/tools/rust-analyzer/crates/mbe/src/lib.rs
+++ b/src/tools/rust-analyzer/crates/mbe/src/lib.rs
@@ -21,7 +21,7 @@ mod token_map;
 use std::fmt;
 
 use crate::{
-    parser::{MetaTemplate, Op},
+    parser::{MetaTemplate, MetaVarKind, Op},
     tt_iter::TtIter,
 };
 
@@ -291,9 +291,9 @@ fn validate(pattern: &MetaTemplate) -> Result<(), ParseError> {
                 // Checks that no repetition which could match an empty token
                 // https://github.com/rust-lang/rust/blob/a58b1ed44f5e06976de2bdc4d7dc81c36a96934f/src/librustc_expand/mbe/macro_rules.rs#L558
                 let lsh_is_empty_seq = separator.is_none() && subtree.iter().all(|child_op| {
-                    match child_op {
+                    match *child_op {
                         // vis is optional
-                        Op::Var { kind: Some(kind), .. } => kind == "vis",
+                        Op::Var { kind: Some(kind), .. } => kind == MetaVarKind::Vis,
                         Op::Repeat {
                             kind: parser::RepeatKind::ZeroOrMore | parser::RepeatKind::ZeroOrOne,
                             ..
diff --git a/src/tools/rust-analyzer/crates/mbe/src/parser.rs b/src/tools/rust-analyzer/crates/mbe/src/parser.rs
index acb4be584..351c359b7 100644
--- a/src/tools/rust-analyzer/crates/mbe/src/parser.rs
+++ b/src/tools/rust-analyzer/crates/mbe/src/parser.rs
@@ -50,7 +50,7 @@ impl MetaTemplate {
 
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub(crate) enum Op {
-    Var { name: SmolStr, kind: Option<SmolStr>, id: tt::TokenId },
+    Var { name: SmolStr, kind: Option<MetaVarKind>, id: tt::TokenId },
     Ignore { name: SmolStr, id: tt::TokenId },
     Index { depth: u32 },
     Repeat { tokens: MetaTemplate, kind: RepeatKind, separator: Option<Separator> },
@@ -65,6 +65,24 @@ pub(crate) enum RepeatKind {
     ZeroOrOne,
 }
 
+#[derive(Copy, Clone, Debug, PartialEq, Eq)]
+pub(crate) enum MetaVarKind {
+    Path,
+    Ty,
+    Pat,
+    PatParam,
+    Stmt,
+    Block,
+    Meta,
+    Item,
+    Vis,
+    Expr,
+    Ident,
+    Tt,
+    Lifetime,
+    Literal,
+}
+
 #[derive(Clone, Debug, Eq)]
 pub(crate) enum Separator {
     Literal(tt::Literal),
@@ -179,13 +197,30 @@ fn next_op<'a>(first: &tt::TokenTree, src: &mut TtIter<'a>, mode: Mode) -> Resul
     Ok(res)
 }
 
-fn eat_fragment_kind(src: &mut TtIter<'_>, mode: Mode) -> Result<Option<SmolStr>, ParseError> {
+fn eat_fragment_kind(src: &mut TtIter<'_>, mode: Mode) -> Result<Option<MetaVarKind>, ParseError> {
     if let Mode::Pattern = mode {
         src.expect_char(':').map_err(|()| ParseError::unexpected("missing fragment specifier"))?;
         let ident = src
             .expect_ident()
             .map_err(|()| ParseError::unexpected("missing fragment specifier"))?;
-        return Ok(Some(ident.text.clone()));
+        let kind = match ident.text.as_str() {
+            "path" => MetaVarKind::Path,
+            "ty" => MetaVarKind::Ty,
+            "pat" => MetaVarKind::Pat,
+            "pat_param" => MetaVarKind::PatParam,
+            "stmt" => MetaVarKind::Stmt,
+            "block" => MetaVarKind::Block,
+            "meta" => MetaVarKind::Meta,
+            "item" => MetaVarKind::Item,
+            "vis" => MetaVarKind::Vis,
+            "expr" => MetaVarKind::Expr,
+            "ident" => MetaVarKind::Ident,
+            "tt" => MetaVarKind::Tt,
+            "lifetime" => MetaVarKind::Lifetime,
+            "literal" => MetaVarKind::Literal,
+            _ => return Ok(None),
+        };
+        return Ok(Some(kind));
     };
     Ok(None)
 }