Properly emit expected ; on #[attr] expr

Author: ShE3py

compiler/rustc_parse/src/parser/diagnostics.rs

@@ -800,9 +800,8 @@ impl<'a> Parser<'a> {
  {
  Ok(next_attr) => next_attr,
  Err(inner_err) => {
- err.cancel();
  inner_err.cancel();
- return self.dcx().span_delayed_bug(expr.span, "not a tail expression");
+ return err.emit();
  }
  }
  && let ast::AttrKind::Normal(next_attr_kind) = next_attr.kind
@@ -813,9 +812,8 @@ impl<'a> Parser<'a> {
  let next_expr = match snapshot.parse_expr() {
  Ok(next_expr) => next_expr,
  Err(inner_err) => {
- err.cancel();
  inner_err.cancel();
- return self.dcx().span_delayed_bug(expr.span, "not a tail expression");
+ return err.emit();
  }
  };
  // We have for sure

tests/ui/parser/attribute/properly-recover-from-trailing-outer-attribute-in-body.rs renamed to tests/ui/parser/attribute/properly-recover-from-trailing-outer-attribute-in-body-1.rs

@@ -1,5 +1,5 @@
 error: expected `;`, found `#`
- --> $DIR/properly-recover-from-trailing-outer-attribute-in-body.rs:4:47
+ --> $DIR/properly-recover-from-trailing-outer-attribute-in-body-1.rs:4:47
  |
 LL | #[cfg(feature = )]
  | ------------------ only `;` terminated statements or tail expressions are allowed after this attribute
@@ -18,7 +18,7 @@ LL | { [1, 2, 3].iter().map().collect::<String>() }
  | + +
 
 error: expected statement after outer attribute
- --> $DIR/properly-recover-from-trailing-outer-attribute-in-body.rs:5:5
+ --> $DIR/properly-recover-from-trailing-outer-attribute-in-body-1.rs:5:5
  |
 LL | #[attr]
  | ^^^^^^^

tests/ui/parser/attribute/properly-recover-from-trailing-outer-attribute-in-body.stderr renamed to tests/ui/parser/attribute/properly-recover-from-trailing-outer-attribute-in-body-1.stderr

@@ -0,0 +1,15 @@
+// Issue #121647: recovery path leaving unemitted error behind
+
+macro_rules! the_macro {
+ ( $foo:stmt ; $bar:stmt ; ) => {
+ #[cfg()]
+ $foo //~ ERROR expected `;`, found `#`
+
+ #[cfg(bar)]
+ $bar
+ };
+}
+
+fn main() {
+ the_macro!( (); (); );
+}

tests/ui/parser/attribute/properly-recover-from-trailing-outer-attribute-in-body-2.rs

@@ -0,0 +1,26 @@
+error: expected `;`, found `#`
+ --> $DIR/properly-recover-from-trailing-outer-attribute-in-body-2.rs:6:13
+ |
+LL | #[cfg()]
+ | -------- only `;` terminated statements or tail expressions are allowed after this attribute
+LL | $foo
+ | ^ expected `;` here
+LL |
+LL | #[cfg(bar)]
+ | - unexpected token
+...
+LL | the_macro!( (); (); );
+ | --------------------- in this macro invocation
+ |
+ = note: this error originates in the macro `the_macro` (in Nightly builds, run with -Z macro-backtrace for more info)
+help: add `;` here
+ |
+LL | $foo;
+ | +
+help: alternatively, consider surrounding the expression with a block
+ |
+LL | the_macro!( { () }; (); );
+ | + +
+
+error: aborting due to 1 previous error
+