string is not a keyword

crates/parser/src/edition.rs

@@ -19,6 +19,10 @@ impl Edition {
     pub fn at_least_2024(self) -> bool {
         self >= Edition::Edition2024
     }
+
+    pub fn at_least_2018(self) -> bool {
+        self >= Edition::Edition2018
+    }
 }
 
 #[derive(Debug)]

crates/parser/src/lexed_str.rs

@@ -178,6 +178,12 @@ impl<'a> Converter<'a> {
                 rustc_lexer::TokenKind::Whitespace => WHITESPACE,
 
                 rustc_lexer::TokenKind::Ident if token_text == "_" => UNDERSCORE,
+                rustc_lexer::TokenKind::Ident
+                    if ["async", "await", "dyn", "try"].contains(&token_text)
+                        && !self.edition.at_least_2018() =>
+                {
+                    IDENT
+                }
                 rustc_lexer::TokenKind::Ident
                     if token_text == "gen" && !self.edition.at_least_2024() =>
                 {

crates/syntax/rust.ungram

@@ -193,7 +193,7 @@ Fn =
  (body:BlockExpr | ';')
 
 Abi =
-  'extern' 'string'?
+  'extern' '@string'?
 
 ParamList =
   '('(

xtask/src/codegen/grammar.rs

@@ -484,6 +484,7 @@ fn generate_syntax_kinds(grammar: KindsSrc) -> String {
             [lifetime_ident] => { $crate::SyntaxKind::LIFETIME_IDENT };
             [int_number] => { $crate::SyntaxKind::INT_NUMBER };
             [ident] => { $crate::SyntaxKind::IDENT };
+            [string] => { $crate::SyntaxKind::STRING };
             [shebang] => { $crate::SyntaxKind::SHEBANG };
         }
     };