Fix case where AST failed to parse to give better errors

src/librustdoc/doctest.rs

@@ -603,6 +603,11 @@ impl DocTest {
  // If `test_id` is `None`, it means we're generating code for a code example "run" link.
  test_id: Option<&str>,
  ) -> (String, usize) {
+ if self.failed_ast {
+ // If the AST failed to compile, no need to go generate a complete doctest, the error
+ // will be better this way.
+ return (self.everything_else.clone(), 0);
+ }
  let mut line_offset = 0;
  let mut prog = String::with_capacity(
  self.test_code.len() + self.crate_attrs.len() + self.crates.len(),
@@ -942,11 +947,10 @@ pub(crate) fn make_test(
  Ok(p) => p,
  Err(errs) => {
  errs.into_iter().for_each(|err| err.cancel());
- return (found_main, found_extern_crate, found_macro, true);
+ return (found_main, found_extern_crate, found_macro);
  }
  };
 
- let mut has_errors = false;
  loop {
  match parser.parse_item(ForceCollect::No) {
  Ok(Some(item)) => {
@@ -977,7 +981,6 @@ pub(crate) fn make_test(
  Ok(None) => break,
  Err(e) => {
  e.cancel();
- has_errors = true;
  break;
  }
  }
@@ -987,14 +990,13 @@ pub(crate) fn make_test(
  parser.maybe_consume_incorrect_semicolon(&[]);
  }
 
- has_errors = has_errors || psess.dcx.has_errors_or_delayed_bugs().is_some();
  // Reset errors so that they won't be reported as compiler bugs when dropping the
  // dcx. Any errors in the tests will be reported when the test file is compiled,
  // Note that we still need to cancel the errors above otherwise `Diag` will panic on
  // drop.
  psess.dcx.reset_err_count();
 
- (found_main, found_extern_crate, found_macro, has_errors)
+ (found_main, found_extern_crate, found_macro)
  })
  });
 
@@ -1003,7 +1005,7 @@ pub(crate) fn make_test(
  Ignore::None => false,
  Ignore::Some(ref ignores) => ignores.iter().any(|s| target_str.contains(s)),
  };
- let Ok((mut main_fn_span, already_has_extern_crate, found_macro, has_errors)) = result else {
+ let Ok((mut main_fn_span, already_has_extern_crate, found_macro)) = result else {
  // If the parser panicked due to a fatal error, pass the test code through unchanged.
  // The error will be reported during compilation.
  return DocTest {
@@ -1059,7 +1061,7 @@ pub(crate) fn make_test(
  lang_string,
  line,
  file,
- failed_ast: has_errors,
+ failed_ast: false,
  rustdoc_test_options,
  outdir,
  test_id,