Fix pretty printer statement boundaries after braced macro call

Author: dtolnay

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

@@ -128,11 +128,7 @@ impl FixupContext {
     /// The documentation on `FixupContext::leftmost_subexpression_in_stmt` has
     /// examples.
     pub fn would_cause_statement_boundary(self, expr: &Expr) -> bool {
-        self.leftmost_subexpression_in_stmt
-            && match expr.kind {
-                ExprKind::MacCall(_) => false,
-                _ => !classify::expr_requires_semi_to_be_stmt(expr),
-            }
+        self.leftmost_subexpression_in_stmt && !classify::expr_requires_semi_to_be_stmt(expr)
     }
 
     /// Determine whether parentheses are needed around the given `let`

tests/ui/macros/stringify.rs

@@ -225,7 +225,7 @@ fn test_expr() {
     );
     c2_match_arm!(
         [ m! {} - 1 ],
-        "match () { _ => m! {} - 1, }",
+        "match () { _ => (m! {}) - 1, }", // parenthesis is redundant
         "match () { _ => m! {} - 1 }",
     );
 
@@ -747,7 +747,7 @@ fn test_stmt() {
     );
     c2_minus_one!(
         [ m! {} ],
-        "m! {} - 1;", // FIXME(dtolnay): needs parens, otherwise this is 2 separate statements
+        "(m! {}) - 1;",
         "m! {} - 1"
     );