Fix stmt boundary after None-delimited group containing loop

dtolnay · Dec 11, 2023 · a2112d4 · a2112d4
1 parent 2781584
commit a2112d4
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Showing 2 changed files with 31 additions and 4 deletions.
diff --git a/src/expr.rs b/src/expr.rs
@@ -1915,7 +1915,15 @@ pub(crate) mod parsing {
     #[cfg(feature = "full")]
     pub(crate) fn expr_early(input: ParseStream) -> Result<Expr> {
         let mut attrs = input.call(expr_attrs)?;
-        let mut expr = if input.peek(Token![if]) {
+        let mut expr = if input.peek(token::Group) {
+            let allow_struct = AllowStruct(true);
+            let atom = expr_group(input, allow_struct)?;
+            if continue_parsing_arm(&atom) {
+                trailer_helper(input, atom)?
+            } else {
+                atom
+            }
+        } else if input.peek(Token![if]) {
             Expr::If(input.parse()?)
         } else if input.peek(Token![while]) {
             Expr::While(input.parse()?)
@@ -1939,13 +1947,16 @@ pub(crate) mod parsing {
             atom_labeled(input)?
         } else {
             let allow_struct = AllowStruct(true);
-            let mut expr = unary_expr(input, allow_struct)?;
+            unary_expr(input, allow_struct)?
+        };
 
+        if continue_parsing_arm(&expr) {
             attrs.extend(expr.replace_attrs(Vec::new()));
             expr.replace_attrs(attrs);
 
+            let allow_struct = AllowStruct(true);
             return parse_expr(input, expr, allow_struct, Precedence::Any);
-        };
+        }
 
         if input.peek(Token![.]) && !input.peek(Token![..]) || input.peek(Token![?]) {
             expr = trailer_helper(input, expr)?;
@@ -1962,6 +1973,23 @@ pub(crate) mod parsing {
         Ok(expr)
     }
 
+    #[cfg(feature = "full")]
+    fn continue_parsing_arm(early: &Expr) -> bool {
+        match early {
+            Expr::If(_)
+            | Expr::While(_)
+            | Expr::ForLoop(_)
+            | Expr::Loop(_)
+            | Expr::Match(_)
+            | Expr::TryBlock(_)
+            | Expr::Unsafe(_)
+            | Expr::Const(_)
+            | Expr::Block(_) => false,
+            Expr::Group(group) => continue_parsing_arm(&group.expr),
+            _ => true,
+        }
+    }
+
     #[cfg_attr(doc_cfg, doc(cfg(feature = "parsing")))]
     impl Parse for ExprLit {
         fn parse(input: ParseStream) -> Result<Self> {

diff --git a/tests/test_expr.rs b/tests/test_expr.rs
@@ -272,7 +272,6 @@ fn test_macro_variable_match_arm() {
 
     let expr = Group::new(Delimiter::None, quote!(loop {} + 1));
     let tokens = quote!(match v { _ => #expr });
-    // FIXME
     snapshot!(tokens as Expr, @r###"
     Expr::Match {
         expr: Expr::Path {