Unify rustc and rustdoc parsing of `cfg()`

This extracts a new `parse_cfg` function that's used between both.

- Treat `#[doc(cfg(x), cfg(y))]` the same as `#[doc(cfg(x)]
  #[doc(cfg(y))]`. Previously it would be completely ignored.
- Treat `#[doc(inline, cfg(x))]` the same as `#[doc(inline)]
  #[doc(cfg(x))]`. Previously, the cfg would be ignored.
- Pass the cfg predicate through to rustc_expand to be validated

Co-authored-by: Vadim Petrochenkov <vadim.petrochenkov@gmail.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/src/librustdoc/doctest.rs b/src/librustdoc/doctest.rs
index 466d1b65406..69a47c5b67a 100644
--- a/src/librustdoc/doctest.rs
+++ b/src/librustdoc/doctest.rs
@@ -1095,7 +1095,7 @@ impl<'a, 'hir, 'tcx> HirCollector<'a, 'hir, 'tcx> {
         let ast_attrs = self.tcx.hir().attrs(hir_id);
         let mut attrs = Attributes::from_ast(ast_attrs, None);
 
-        if let Some(ref cfg) = ast_attrs.cfg(self.sess.diagnostic()) {
+        if let Some(ref cfg) = ast_attrs.cfg(self.sess) {
             if !cfg.matches(&self.sess.parse_sess, Some(&self.sess.features_untracked())) {
                 return;
             }