let #[allow_internal_unstable] cover :vis

src/libsyntax/ext/tt/macro_rules.rs

@@ -210,7 +210,7 @@ pub fn compile(sess: &ParseSess, features: &RefCell<Features>, def: &ast::Item)
  if let MatchedNonterminal(ref nt) = **m {
  if let NtTT(ref tt) = **nt {
  let tt = quoted::parse(tt.clone().into(), true, sess).pop().unwrap();
- valid &= check_lhs_nt_follows(sess, features, &tt);
+ valid &= check_lhs_nt_follows(sess, features, &def.attrs, &tt);
  return tt;
  }
  }
@@ -255,11 +255,12 @@ pub fn compile(sess: &ParseSess, features: &RefCell<Features>, def: &ast::Item)
 
 fn check_lhs_nt_follows(sess: &ParseSess,
  features: &RefCell<Features>,
+ attrs: &[ast::Attribute],
  lhs: &quoted::TokenTree) -> bool {
  // lhs is going to be like TokenTree::Delimited(...), where the
  // entire lhs is those tts. Or, it can be a "bare sequence", not wrapped in parens.
  match lhs {
- &quoted::TokenTree::Delimited(_, ref tts) => check_matcher(sess, features, &tts.tts),
+ &quoted::TokenTree::Delimited(_, ref tts) => check_matcher(sess, features, attrs, &tts.tts),
  _ => {
  let msg = "invalid macro matcher; matchers must be contained in balanced delimiters";
  sess.span_diagnostic.span_err(lhs.span(), msg);
@@ -313,11 +314,12 @@ fn check_rhs(sess: &ParseSess, rhs: &quoted::TokenTree) -> bool {
 
 fn check_matcher(sess: &ParseSess,
  features: &RefCell<Features>,
+ attrs: &[ast::Attribute],
  matcher: &[quoted::TokenTree]) -> bool {
  let first_sets = FirstSets::new(matcher);
  let empty_suffix = TokenSet::empty();
  let err = sess.span_diagnostic.err_count();
- check_matcher_core(sess, features, &first_sets, matcher, &empty_suffix);
+ check_matcher_core(sess, features, attrs, &first_sets, matcher, &empty_suffix);
  err == sess.span_diagnostic.err_count()
 }
 
@@ -560,6 +562,7 @@ impl TokenSet {
 // see `FirstSets::new`.
 fn check_matcher_core(sess: &ParseSess,
  features: &RefCell<Features>,
+ attrs: &[ast::Attribute],
  first_sets: &FirstSets,
  matcher: &[quoted::TokenTree],
  follow: &TokenSet) -> TokenSet {
@@ -590,7 +593,7 @@ fn check_matcher_core(sess: &ParseSess,
  match *token {
  TokenTree::Token(..) | TokenTree::MetaVarDecl(..) => {
  let can_be_followed_by_any;
- if let Err(bad_frag) = has_legal_fragment_specifier(sess, features, token) {
+ if let Err(bad_frag) = has_legal_fragment_specifier(sess, features, attrs, token) {
  let msg = format!("invalid fragment specifier `{}`", bad_frag);
  sess.span_diagnostic.struct_span_err(token.span(), &msg)
  .help("valid fragment specifiers are `ident`, `block`, `stmt`, `expr`, \
@@ -616,7 +619,7 @@ fn check_matcher_core(sess: &ParseSess,
  }
  TokenTree::Delimited(span, ref d) => {
  let my_suffix = TokenSet::singleton(d.close_tt(span));
- check_matcher_core(sess, features, first_sets, &d.tts, &my_suffix);
+ check_matcher_core(sess, features, attrs, first_sets, &d.tts, &my_suffix);
  // don't track non NT tokens
  last.replace_with_irrelevant();
 
@@ -648,7 +651,12 @@ fn check_matcher_core(sess: &ParseSess,
  // At this point, `suffix_first` is built, and
  // `my_suffix` is some TokenSet that we can use
  // for checking the interior of `seq_rep`.
- let next = check_matcher_core(sess, features, first_sets, &seq_rep.tts, my_suffix);
+ let next = check_matcher_core(sess,
+ features,
+ attrs,
+ first_sets,
+ &seq_rep.tts,
+ my_suffix);
  if next.maybe_empty {
  last.add_all(&next);
  } else {
@@ -821,12 +829,13 @@ fn is_in_follow(tok: &quoted::TokenTree, frag: &str) -> Result<bool, (String, &'
 
 fn has_legal_fragment_specifier(sess: &ParseSess,
  features: &RefCell<Features>,
+ attrs: &[ast::Attribute],
  tok: &quoted::TokenTree) -> Result<(), String> {
  debug!("has_legal_fragment_specifier({:?})", tok);
  if let quoted::TokenTree::MetaVarDecl(_, _, ref frag_spec) = *tok {
  let frag_name = frag_spec.name.as_str();
  let frag_span = tok.span();
- if !is_legal_fragment_specifier(sess, features, &frag_name, frag_span) {
+ if !is_legal_fragment_specifier(sess, features, attrs, &frag_name, frag_span) {
  return Err(frag_name.to_string());
  }
  }
@@ -835,13 +844,15 @@ fn has_legal_fragment_specifier(sess: &ParseSess,
 
 fn is_legal_fragment_specifier(sess: &ParseSess,
  features: &RefCell<Features>,
+ attrs: &[ast::Attribute],
  frag_name: &str,
  frag_span: Span) -> bool {
  match frag_name {
  "item" | "block" | "stmt" | "expr" | "pat" |
  "path" | "ty" | "ident" | "meta" | "tt" | "" => true,
  "vis" => {
- if !features.borrow().macro_vis_matcher {
+ if !features.borrow().macro_vis_matcher
+ && !attr::contains_name(attrs, "allow_internal_unstable") {
  let explain = feature_gate::EXPLAIN_VIS_MATCHER;
  emit_feature_err(sess,
  "macro_vis_matcher",