diff options
Diffstat (limited to 'src/libsyntax/feature_gate.rs')
| -rw-r--r-- | src/libsyntax/feature_gate.rs | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/src/libsyntax/feature_gate.rs b/src/libsyntax/feature_gate.rs index 91364fe6ed4..767c806bc71 100644 --- a/src/libsyntax/feature_gate.rs +++ b/src/libsyntax/feature_gate.rs @@ -455,6 +455,9 @@ declare_features! ( // Parentheses in patterns (active, pattern_parentheses, "1.26.0", None, None), + + // `use path as _;` and `extern crate c as _;` + (active, underscore_imports, "1.26.0", Some(48216), None), ); declare_features! ( @@ -1436,9 +1439,24 @@ impl<'a> Visitor<'a> for PostExpansionVisitor<'a> { } } + fn visit_use_tree(&mut self, use_tree: &'a ast::UseTree, id: NodeId, _nested: bool) { + if let ast::UseTreeKind::Simple(ident) = use_tree.kind { + if ident.name == "_" { + gate_feature_post!(&self, underscore_imports, use_tree.span, + "renaming imports with `_` is unstable"); + } + } + + visit::walk_use_tree(self, use_tree, id); + } + fn visit_item(&mut self, i: &'a ast::Item) { match i.node { ast::ItemKind::ExternCrate(_) => { + if i.ident.name == "_" { + gate_feature_post!(&self, underscore_imports, i.span, + "renaming extern crates with `_` is unstable"); + } if let Some(attr) = attr::find_by_name(&i.attrs[..], "macro_reexport") { gate_feature_post!(&self, macro_reexport, attr.span, "macros re-exports are experimental \ |