6 files changed, 79 insertions, 53 deletions

diff --git a/crates/parser/src/grammar.rs b/crates/parser/src/grammar.rs
index cebb8f400..9bdf0b5fa 100644
--- a/crates/parser/src/grammar.rs
+++ b/crates/parser/src/grammar.rs
@@ -76,42 +76,7 @@ pub(crate) mod fragments {
 
     // Parse a meta item , which excluded [], e.g : #[ MetaItem ]
     pub(crate) fn meta_item(p: &mut Parser) {
-        fn is_delimiter(p: &mut Parser) -> bool {
-            matches!(p.current(), T!['{'] | T!['('] | T!['['])
-        }
-
-        if is_delimiter(p) {
-            items::token_tree(p);
-            return;
-        }
-
-        let m = p.start();
-        while !p.at(EOF) {
-            if is_delimiter(p) {
-                items::token_tree(p);
-                break;
-            } else {
-                // https://doc.rust-lang.org/reference/attributes.html
-                // https://doc.rust-lang.org/reference/paths.html#simple-paths
-                // The start of an meta must be a simple path
-                match p.current() {
-                    IDENT | T![super] | T![self] | T![crate] => p.bump_any(),
-                    T![=] => {
-                        p.bump_any();
-                        match p.current() {
-                            c if c.is_literal() => p.bump_any(),
-                            T![true] | T![false] => p.bump_any(),
-                            _ => {}
-                        }
-                        break;
-                    }
-                    _ if p.at(T![::]) => p.bump(T![::]),
-                    _ => break,
-                }
-            }
-        }
-
-        m.complete(p, TOKEN_TREE);
+        attributes::meta(p);
     }
 
     pub(crate) fn item(p: &mut Parser) {
diff --git a/crates/parser/src/grammar/attributes.rs b/crates/parser/src/grammar/attributes.rs
index 96791ffc2..124a10eb2 100644
--- a/crates/parser/src/grammar/attributes.rs
+++ b/crates/parser/src/grammar/attributes.rs
@@ -14,6 +14,21 @@ pub(super) fn outer_attrs(p: &mut Parser) {
     }
 }
 
+pub(super) fn meta(p: &mut Parser) {
+    paths::use_path(p);
+
+    match p.current() {
+        T![=] => {
+            p.bump(T![=]);
+            if expressions::expr(p).0.is_none() {
+                p.error("expected expression");
+            }
+        }
+        T!['('] | T!['['] | T!['{'] => items::token_tree(p),
+        _ => {}
+    }
+}
+
 fn attr(p: &mut Parser, inner: bool) {
     let attr = p.start();
     assert!(p.at(T![#]));
@@ -25,18 +40,7 @@ fn attr(p: &mut Parser, inner: bool) {
     }
 
     if p.eat(T!['[']) {
-        paths::use_path(p);
-
-        match p.current() {
-            T![=] => {
-                p.bump(T![=]);
-                if expressions::expr(p).0.is_none() {
-                    p.error("expected expression");
-                }
-            }
-            T!['('] | T!['['] | T!['{'] => items::token_tree(p),
-            _ => {}
-        }
+        meta(p);
 
         if !p.eat(T![']']) {
             p.error("expected `]`");
diff --git a/crates/parser/src/grammar/patterns.rs b/crates/parser/src/grammar/patterns.rs
index da71498a8..3ab347834 100644
--- a/crates/parser/src/grammar/patterns.rs
+++ b/crates/parser/src/grammar/patterns.rs
@@ -206,13 +206,15 @@ fn record_pat_field_list(p: &mut Parser) {
             T![.] if p.at(T![..]) => p.bump(T![..]),
             T!['{'] => error_block(p, "expected ident"),
 
-            c => {
+            _ => {
                 let m = p.start();
-                match c {
+                attributes::outer_attrs(p);
+                match p.current() {
                     // test record_pat_field
                     // fn foo() {
                     //     let S { 0: 1 } = ();
                     //     let S { x: 1 } = ();
+                    //     let S { #[cfg(any())] x: 1 } = ();
                     // }
                     IDENT | INT_NUMBER if p.nth(1) == T![:] => {
                         name_ref_or_index(p);
diff --git a/crates/parser/src/grammar/type_args.rs b/crates/parser/src/grammar/type_args.rs
index 42cd426bd..be36cad17 100644
--- a/crates/parser/src/grammar/type_args.rs
+++ b/crates/parser/src/grammar/type_args.rs
@@ -25,6 +25,38 @@ pub(super) fn opt_generic_arg_list(p: &mut Parser, colon_colon_required: bool) {
     m.complete(p, GENERIC_ARG_LIST);
 }
 
+pub(super) fn const_arg(p: &mut Parser) {
+    let m = p.start();
+    // FIXME: duplicates the code below
+    match p.current() {
+        T!['{'] => {
+            expressions::block_expr(p);
+            m.complete(p, CONST_ARG);
+        }
+        k if k.is_literal() => {
+            expressions::literal(p);
+            m.complete(p, CONST_ARG);
+        }
+        T![true] | T![false] => {
+            expressions::literal(p);
+            m.complete(p, CONST_ARG);
+        }
+        T![-] => {
+            let lm = p.start();
+            p.bump(T![-]);
+            expressions::literal(p);
+            lm.complete(p, PREFIX_EXPR);
+            m.complete(p, CONST_ARG);
+        }
+        _ => {
+            let lm = p.start();
+            paths::use_path(p);
+            lm.complete(p, PATH_EXPR);
+            m.complete(p, CONST_ARG);
+        }
+    }
+}
+
 // test type_arg
 // type A = B<'static, i32, 1, { 2 }, Item=u64, true, false>;
 fn generic_arg(p: &mut Parser) {
@@ -59,6 +91,15 @@ fn generic_arg(p: &mut Parser) {
             expressions::literal(p);
             m.complete(p, CONST_ARG);
         }
+        // test const_generic_negated_literal
+        // fn f() { S::<-1> }
+        T![-] => {
+            let lm = p.start();
+            p.bump(T![-]);
+            expressions::literal(p);
+            lm.complete(p, PREFIX_EXPR);
+            m.complete(p, CONST_ARG);
+        }
         _ => {
             types::type_(p);
             m.complete(p, TYPE_ARG);
diff --git a/crates/parser/src/grammar/type_params.rs b/crates/parser/src/grammar/type_params.rs
index 3de5248da..b1f979281 100644
--- a/crates/parser/src/grammar/type_params.rs
+++ b/crates/parser/src/grammar/type_params.rs
@@ -70,6 +70,16 @@ fn const_param(p: &mut Parser, m: Marker) {
     p.bump(T![const]);
     name(p);
     types::ascription(p);
+
+    // test const_param_defaults
+    // struct A<const N: i32 = -1>;
+    // struct B<const N: i32 = {}>;
+    // struct C<const N: i32 = some::CONST>;
+    if p.at(T![=]) {
+        p.bump(T![=]);
+        type_args::const_arg(p);
+    }
+
     m.complete(p, CONST_PARAM);
 }
 
diff --git a/crates/parser/src/grammar/types.rs b/crates/parser/src/grammar/types.rs
index 94cbf7d85..6ae3e734f 100644
--- a/crates/parser/src/grammar/types.rs
+++ b/crates/parser/src/grammar/types.rs
@@ -283,17 +283,21 @@ pub(super) fn path_type(p: &mut Parser) {
 // type B = crate::foo!();
 fn path_or_macro_type_(p: &mut Parser, allow_bounds: bool) {
     assert!(paths::is_path_start(p));
+    let r = p.start();
     let m = p.start();
+
     paths::type_path(p);
 
     let kind = if p.at(T![!]) && !p.at(T![!=]) {
         items::macro_call_after_excl(p);
-        MACRO_CALL
+        m.complete(p, MACRO_CALL);
+        MACRO_TYPE
     } else {
+        m.abandon(p);
         PATH_TYPE
     };
 
-    let path = m.complete(p, kind);
+    let path = r.complete(p, kind);
 
     if allow_bounds {
         opt_type_bounds_as_dyn_trait_type(p, path);
@@ -319,7 +323,7 @@ pub(super) fn path_type_(p: &mut Parser, allow_bounds: bool) {
 fn opt_type_bounds_as_dyn_trait_type(p: &mut Parser, type_marker: CompletedMarker) {
     assert!(matches!(
         type_marker.kind(),
-        SyntaxKind::PATH_TYPE | SyntaxKind::FOR_TYPE | SyntaxKind::MACRO_CALL
+        SyntaxKind::PATH_TYPE | SyntaxKind::FOR_TYPE | SyntaxKind::MACRO_TYPE
     ));
     if !p.at(T![+]) {
         return;