diff --git a/src/librustc/middle/lib_features.rs b/src/librustc/middle/lib_features.rs index 47c6bfbe694..c21ac621803 100644 --- a/src/librustc/middle/lib_features.rs +++ b/src/librustc/middle/lib_features.rs @@ -18,8 +18,7 @@ use ty::TyCtxt; use syntax::symbol::Symbol; use syntax::ast::{Attribute, MetaItem, MetaItemKind}; use syntax_pos::{Span, DUMMY_SP}; -use hir; -use hir::itemlikevisit::ItemLikeVisitor; +use hir::intravisit::{self, NestedVisitorMap, Visitor}; use rustc_data_structures::fx::{FxHashSet, FxHashMap}; use errors::DiagnosticId; @@ -59,47 +58,44 @@ impl<'a, 'tcx> LibFeatureCollector<'a, 'tcx> { } } - fn extract(&self, attrs: &[Attribute]) -> Vec<(Symbol, Option<Symbol>, Span)> { + fn extract(&self, attr: &Attribute) -> Option<(Symbol, Option<Symbol>, Span)> { let stab_attrs = vec!["stable", "unstable", "rustc_const_unstable"]; - let mut features = vec![]; - for attr in attrs { - // Find a stability attribute (i.e. `#[stable (..)]`, `#[unstable (..)]`, - // `#[rustc_const_unstable (..)]`). - if let Some(stab_attr) = stab_attrs.iter().find(|stab_attr| { - attr.check_name(stab_attr) - }) { - let meta_item = attr.meta(); - if let Some(MetaItem { node: MetaItemKind::List(ref metas), .. }) = meta_item { - let mut feature = None; - let mut since = None; - for meta in metas { - if let Some(mi) = meta.meta_item() { - // Find the `feature = ".."` meta-item. - match (&*mi.name().as_str(), mi.value_str()) { - ("feature", val) => feature = val, - ("since", val) => since = val, - _ => {} - } + // Find a stability attribute (i.e. `#[stable (..)]`, `#[unstable (..)]`, + // `#[rustc_const_unstable (..)]`). + if let Some(stab_attr) = stab_attrs.iter().find(|stab_attr| { + attr.check_name(stab_attr) + }) { + let meta_item = attr.meta(); + if let Some(MetaItem { node: MetaItemKind::List(ref metas), .. }) = meta_item { + let mut feature = None; + let mut since = None; + for meta in metas { + if let Some(mi) = meta.meta_item() { + // Find the `feature = ".."` meta-item. + match (&*mi.name().as_str(), mi.value_str()) { + ("feature", val) => feature = val, + ("since", val) => since = val, + _ => {} } } - if let Some(feature) = feature { - // This additional check for stability is to make sure we - // don't emit additional, irrelevant errors for malformed - // attributes. - if *stab_attr != "stable" || since.is_some() { - features.push((feature, since, attr.span)); - } - } - // We need to iterate over the other attributes, because - // `rustc_const_unstable` is not mutually exclusive with - // the other stability attributes, so we can't just `break` - // here. } + if let Some(feature) = feature { + // This additional check for stability is to make sure we + // don't emit additional, irrelevant errors for malformed + // attributes. + if *stab_attr != "stable" || since.is_some() { + return Some((feature, since, attr.span)); + } + } + // We need to iterate over the other attributes, because + // `rustc_const_unstable` is not mutually exclusive with + // the other stability attributes, so we can't just `break` + // here. } } - features + None } fn collect_feature(&mut self, feature: Symbol, since: Option<Symbol>, span: Span) { @@ -140,25 +136,17 @@ impl<'a, 'tcx> LibFeatureCollector<'a, 'tcx> { } } } - - fn collect_from_attrs(&mut self, attrs: &[Attribute]) { - for (feature, stable, span) in self.extract(attrs) { - self.collect_feature(feature, stable, span); - } - } } -impl<'a, 'v, 'tcx> ItemLikeVisitor<'v> for LibFeatureCollector<'a, 'tcx> { - fn visit_item(&mut self, item: &hir::Item) { - self.collect_from_attrs(&item.attrs); +impl<'a, 'tcx> Visitor<'tcx> for LibFeatureCollector<'a, 'tcx> { + fn nested_visit_map<'this>(&'this mut self) -> NestedVisitorMap<'this, 'tcx> { + NestedVisitorMap::All(&self.tcx.hir) } - fn visit_trait_item(&mut self, trait_item: &hir::TraitItem) { - self.collect_from_attrs(&trait_item.attrs); - } - - fn visit_impl_item(&mut self, impl_item: &hir::ImplItem) { - self.collect_from_attrs(&impl_item.attrs); + fn visit_attribute(&mut self, attr: &'tcx Attribute) { + if let Some((feature, stable, span)) = self.extract(attr) { + self.collect_feature(feature, stable, span); + } } } @@ -169,10 +157,6 @@ pub fn collect<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>) -> LibFeatures { collector.collect_feature(feature, since, DUMMY_SP); } } - collector.collect_from_attrs(&tcx.hir.krate().attrs); - tcx.hir.krate().visit_all_item_likes(&mut collector); - for exported_macro in &tcx.hir.krate().exported_macros { - collector.collect_from_attrs(&exported_macro.attrs); - } + intravisit::walk_crate(&mut collector, tcx.hir.krate()); collector.lib_features }