Fix pretty printer statement boundaries after braced macro call

Author: dtolnay

compiler/rustc_ast_pretty/src/pprust/state/expr.rs

@@ -470,11 +470,8 @@ impl<'a> State<'a> {
         //
         // Same applies to a small set of other expression kinds which eagerly
         // terminate a statement which opens with them.
-        let needs_par = fixup.leftmost_subexpression_in_stmt
-            && match expr.kind {
-                ast::ExprKind::MacCall(_) => false,
-                _ => !classify::expr_requires_semi_to_be_stmt(expr),
-            };
+        let needs_par =
+            fixup.leftmost_subexpression_in_stmt && !classify::expr_requires_semi_to_be_stmt(expr);
         if needs_par {
             self.popen();
             fixup = FixupContext::default();

tests/ui/macros/stringify.rs

@@ -226,7 +226,7 @@ fn test_expr() {
     );
     c2_match_arm!(
         [ m! {} - 1 ],
-        "match () { _ => m! {} - 1, }",
+        "match () { _ => (m! {}) - 1, }", // parenthesis is redundant
         "match() { _ => m! {} - 1 }",
     );
 
@@ -748,7 +748,7 @@ fn test_stmt() {
     );
     c2_minus_one!(
         [ m! {} ],
-        "m! {} - 1;", // FIXME(dtolnay): needs parens, otherwise this is 2 separate statements
+        "(m! {}) - 1;",
         "m! {} - 1"
     );