From 5686a91914ac678ccb78220367daefe585a0d66a Mon Sep 17 00:00:00 2001 From: Niko Matsakis Date: Tue, 9 Dec 2014 19:59:20 -0500 Subject: [PATCH] Parse `unsafe trait` but do not do anything with it beyond parsing and integrating into rustdoc etc. --- src/librustc/lint/builtin.rs | 2 +- src/librustc/metadata/common.rs | 2 ++ src/librustc/metadata/decoder.rs | 5 +++++ src/librustc/metadata/encoder.rs | 11 ++++++++++- src/librustc/middle/privacy.rs | 10 +++++----- src/librustc/middle/resolve.rs | 4 ++-- src/librustc/middle/resolve_lifetime.rs | 2 +- src/librustc/middle/ty.rs | 4 +++- src/librustc_trans/save/mod.rs | 2 +- src/librustc_typeck/check/mod.rs | 2 +- src/librustc_typeck/collect.rs | 12 +++++++----- src/librustc_typeck/variance.rs | 2 +- src/librustdoc/clean/inline.rs | 1 + src/librustdoc/clean/mod.rs | 2 ++ src/librustdoc/doctree.rs | 1 + src/librustdoc/html/render.rs | 3 ++- src/librustdoc/visit_ast.rs | 3 ++- src/libsyntax/ast.rs | 3 ++- src/libsyntax/ast_map/mod.rs | 2 +- src/libsyntax/config.rs | 4 ++-- src/libsyntax/fold.rs | 5 +++-- src/libsyntax/parse/parser.rs | 24 +++++++++++++++++++++--- src/libsyntax/print/pprust.rs | 8 +++++--- src/libsyntax/visit.rs | 2 +- src/test/pretty/trait-safety.rs | 21 +++++++++++++++++++++ 25 files changed, 103 insertions(+), 34 deletions(-) create mode 100644 src/test/pretty/trait-safety.rs diff --git a/src/librustc/lint/builtin.rs b/src/librustc/lint/builtin.rs index e19fa01b2e4..5af7fec4181 100644 --- a/src/librustc/lint/builtin.rs +++ b/src/librustc/lint/builtin.rs @@ -1721,7 +1721,7 @@ impl LintPass for Stability { if self.is_internal(cx, item.span) { return } match item.node { - ast::ItemTrait(_, _, ref supertraits, _) => { + ast::ItemTrait(_, _, _, ref supertraits, _) => { for t in supertraits.iter() { if let ast::TraitTyParamBound(ref t) = *t { let id = ty::trait_ref_to_def_id(cx.tcx, &t.trait_ref); diff --git a/src/librustc/metadata/common.rs b/src/librustc/metadata/common.rs index 99e7966b66f..b698e4fcc7f 100644 --- a/src/librustc/metadata/common.rs +++ b/src/librustc/metadata/common.rs @@ -255,3 +255,5 @@ pub const tag_method_ty_generics: uint = 0xa7; pub const tag_predicate: uint = 0xa8; pub const tag_predicate_space: uint = 0xa9; pub const tag_predicate_data: uint = 0xb0; + +pub const tag_unsafety: uint = 0xb1; diff --git a/src/librustc/metadata/decoder.rs b/src/librustc/metadata/decoder.rs index 4e892f53186..37124286398 100644 --- a/src/librustc/metadata/decoder.rs +++ b/src/librustc/metadata/decoder.rs @@ -368,8 +368,13 @@ pub fn get_trait_def<'tcx>(cdata: Cmd, let item_doc = lookup_item(item_id, cdata.data()); let generics = doc_generics(item_doc, tcx, cdata, tag_item_generics); let bounds = trait_def_bounds(item_doc, tcx, cdata); + let unsafety = match reader::maybe_get_doc(item_doc, tag_unsafety) { + Some(_) => ast::Unsafety::Unsafe, + None => ast::Unsafety::Normal, + }; ty::TraitDef { + unsafety: unsafety, generics: generics, bounds: bounds, trait_ref: Rc::new(item_trait_ref(item_doc, tcx, cdata)) diff --git a/src/librustc/metadata/encoder.rs b/src/librustc/metadata/encoder.rs index 9804e3c20aa..cb8de256448 100644 --- a/src/librustc/metadata/encoder.rs +++ b/src/librustc/metadata/encoder.rs @@ -1308,13 +1308,22 @@ fn encode_info_for_item(ecx: &EncodeContext, } } } - ast::ItemTrait(_, _, _, ref ms) => { + ast::ItemTrait(_, _, _, _, ref ms) => { add_to_index(item, rbml_w, index); rbml_w.start_tag(tag_items_data_item); encode_def_id(rbml_w, def_id); encode_family(rbml_w, 'I'); encode_item_variances(rbml_w, ecx, item.id); let trait_def = ty::lookup_trait_def(tcx, def_id); + + match trait_def.unsafety { + ast::Unsafety::Unsafe => { + rbml_w.start_tag(tag_unsafety); + rbml_w.end_tag(); + } + ast::Unsafety::Normal => { } + } + encode_generics(rbml_w, ecx, &trait_def.generics, tag_item_generics); encode_trait_ref(rbml_w, ecx, &*trait_def.trait_ref, tag_item_trait_ref); encode_name(rbml_w, item.ident.name); diff --git a/src/librustc/middle/privacy.rs b/src/librustc/middle/privacy.rs index 79bb19a1e53..352c2add000 100644 --- a/src/librustc/middle/privacy.rs +++ b/src/librustc/middle/privacy.rs @@ -76,7 +76,7 @@ impl<'v> Visitor<'v> for ParentVisitor { // method to the root. In this case, if the trait is private, then // parent all the methods to the trait to indicate that they're // private. - ast::ItemTrait(_, _, _, ref methods) if item.vis != ast::Public => { + ast::ItemTrait(_, _, _, _, ref methods) if item.vis != ast::Public => { for m in methods.iter() { match *m { ast::ProvidedMethod(ref m) => { @@ -282,7 +282,7 @@ impl<'a, 'tcx, 'v> Visitor<'v> for EmbargoVisitor<'a, 'tcx> { // Default methods on traits are all public so long as the trait // is public - ast::ItemTrait(_, _, _, ref methods) if public_first => { + ast::ItemTrait(_, _, _, _, ref methods) if public_first => { for method in methods.iter() { match *method { ast::ProvidedMethod(ref m) => { @@ -1134,7 +1134,7 @@ impl<'a, 'tcx> SanePrivacyVisitor<'a, 'tcx> { } } - ast::ItemTrait(_, _, _, ref methods) => { + ast::ItemTrait(_, _, _, _, ref methods) => { for m in methods.iter() { match *m { ast::ProvidedMethod(ref m) => { @@ -1198,7 +1198,7 @@ impl<'a, 'tcx> SanePrivacyVisitor<'a, 'tcx> { ast::ItemStruct(ref def, _) => check_struct(&**def), - ast::ItemTrait(_, _, _, ref methods) => { + ast::ItemTrait(_, _, _, _, ref methods) => { for m in methods.iter() { match *m { ast::RequiredMethod(..) => {} @@ -1305,7 +1305,7 @@ impl<'a, 'tcx, 'v> Visitor<'v> for VisiblePrivateTypesVisitor<'a, 'tcx> { // namespace (the contents have their own privacies). ast::ItemForeignMod(_) => {} - ast::ItemTrait(_, _, ref bounds, _) => { + ast::ItemTrait(_, _, _, ref bounds, _) => { if !self.trait_is_public(item.id) { return } diff --git a/src/librustc/middle/resolve.rs b/src/librustc/middle/resolve.rs index f2c83291b79..2e52bab2ae3 100644 --- a/src/librustc/middle/resolve.rs +++ b/src/librustc/middle/resolve.rs @@ -1583,7 +1583,7 @@ impl<'a> Resolver<'a> { ItemImpl(_, Some(_), _, _) => parent, - ItemTrait(_, _, _, ref items) => { + ItemTrait(_, _, _, _, ref items) => { let name_bindings = self.add_child(name, parent.clone(), @@ -4241,7 +4241,7 @@ impl<'a> Resolver<'a> { impl_items.as_slice()); } - ItemTrait(ref generics, ref unbound, ref bounds, ref trait_items) => { + ItemTrait(_, ref generics, ref unbound, ref bounds, ref trait_items) => { // Create a new rib for the self type. let mut self_type_rib = Rib::new(ItemRibKind); diff --git a/src/librustc/middle/resolve_lifetime.rs b/src/librustc/middle/resolve_lifetime.rs index ee0fc327020..683948cd2e7 100644 --- a/src/librustc/middle/resolve_lifetime.rs +++ b/src/librustc/middle/resolve_lifetime.rs @@ -106,7 +106,7 @@ impl<'a, 'v> Visitor<'v> for LifetimeContext<'a> { ast::ItemTy(_, ref generics) | ast::ItemEnum(_, ref generics) | ast::ItemStruct(_, ref generics) | - ast::ItemTrait(ref generics, _, _, _) => { + ast::ItemTrait(_, ref generics, _, _, _) => { // These kinds of items have only early bound lifetime parameters. let lifetimes = &generics.lifetimes; self.with(EarlyScope(subst::TypeSpace, lifetimes, &ROOT_SCOPE), |this| { diff --git a/src/librustc/middle/ty.rs b/src/librustc/middle/ty.rs index 9673b9ab586..4c4df698f33 100644 --- a/src/librustc/middle/ty.rs +++ b/src/librustc/middle/ty.rs @@ -1915,6 +1915,8 @@ pub struct Polytype<'tcx> { /// As `Polytype` but for a trait ref. pub struct TraitDef<'tcx> { + pub unsafety: ast::Unsafety, + /// Generic type definitions. Note that `Self` is listed in here /// as having a single bound, the trait itself (e.g., in the trait /// `Eq`, there is a single bound `Self : Eq`). This is so that @@ -4572,7 +4574,7 @@ pub fn provided_trait_methods<'tcx>(cx: &ctxt<'tcx>, id: ast::DefId) match cx.map.find(id.node) { Some(ast_map::NodeItem(item)) => { match item.node { - ItemTrait(_, _, _, ref ms) => { + ItemTrait(_, _, _, _, ref ms) => { let (_, p) = ast_util::split_trait_methods(ms.as_slice()); p.iter() diff --git a/src/librustc_trans/save/mod.rs b/src/librustc_trans/save/mod.rs index 329241b24e6..779fcd70864 100644 --- a/src/librustc_trans/save/mod.rs +++ b/src/librustc_trans/save/mod.rs @@ -1050,7 +1050,7 @@ impl<'l, 'tcx, 'v> Visitor<'v> for DxrVisitor<'l, 'tcx> { &**typ, impl_items) } - ast::ItemTrait(ref generics, _, ref trait_refs, ref methods) => + ast::ItemTrait(_, ref generics, _, ref trait_refs, ref methods) => self.process_trait(item, generics, trait_refs, methods), ast::ItemMod(ref m) => self.process_mod(item, m), ast::ItemTy(ref ty, ref ty_params) => { diff --git a/src/librustc_typeck/check/mod.rs b/src/librustc_typeck/check/mod.rs index 5b1ca8fc1c0..c64519c96dd 100644 --- a/src/librustc_typeck/check/mod.rs +++ b/src/librustc_typeck/check/mod.rs @@ -625,7 +625,7 @@ pub fn check_item(ccx: &CrateCtxt, it: &ast::Item) { } } - ast::ItemTrait(_, _, _, ref trait_methods) => { + ast::ItemTrait(_, _, _, _, ref trait_methods) => { let trait_def = ty::lookup_trait_def(ccx.tcx, local_def(it.id)); for trait_method in trait_methods.iter() { match *trait_method { diff --git a/src/librustc_typeck/collect.rs b/src/librustc_typeck/collect.rs index 0bb0f95a66b..643d8eb60ce 100644 --- a/src/librustc_typeck/collect.rs +++ b/src/librustc_typeck/collect.rs @@ -258,7 +258,7 @@ fn collect_trait_methods<'a, 'tcx>(ccx: &CrateCtxt<'a, 'tcx>, trait_def: &ty::TraitDef<'tcx>) { let tcx = ccx.tcx; if let ast_map::NodeItem(item) = tcx.map.get(trait_id) { - if let ast::ItemTrait(_, _, _, ref trait_items) = item.node { + if let ast::ItemTrait(_, _, _, _, ref trait_items) = item.node { // For each method, construct a suitable ty::Method and // store it into the `tcx.impl_or_trait_items` table: for trait_item in trait_items.iter() { @@ -1144,7 +1144,7 @@ pub fn convert(ccx: &CrateCtxt, it: &ast::Item) { AllowEqConstraints::DontAllow); } }, - ast::ItemTrait(_, _, _, ref trait_methods) => { + ast::ItemTrait(_, _, _, _, ref trait_methods) => { let trait_def = trait_def_of_item(ccx, it); debug!("trait_def: ident={} trait_def={}", @@ -1335,12 +1335,13 @@ pub fn trait_def_of_item<'a, 'tcx>(ccx: &CrateCtxt<'a, 'tcx>, return def.clone(); } - let (generics, unbound, bounds, items) = match it.node { - ast::ItemTrait(ref generics, + let (unsafety, generics, unbound, bounds, items) = match it.node { + ast::ItemTrait(unsafety, + ref generics, ref unbound, ref supertraits, ref items) => { - (generics, unbound, supertraits, items.as_slice()) + (unsafety, generics, unbound, supertraits, items.as_slice()) } ref s => { tcx.sess.span_bug( @@ -1369,6 +1370,7 @@ pub fn trait_def_of_item<'a, 'tcx>(ccx: &CrateCtxt<'a, 'tcx>, let substs = mk_item_substs(ccx, &ty_generics); let trait_def = Rc::new(ty::TraitDef { + unsafety: unsafety, generics: ty_generics, bounds: bounds, trait_ref: Rc::new(ty::TraitRef { diff --git a/src/librustc_typeck/variance.rs b/src/librustc_typeck/variance.rs index bd7db560d9e..8fe14bae0f5 100644 --- a/src/librustc_typeck/variance.rs +++ b/src/librustc_typeck/variance.rs @@ -358,7 +358,7 @@ impl<'a, 'tcx, 'v> Visitor<'v> for TermsContext<'a, 'tcx> { match item.node { ast::ItemEnum(_, ref generics) | ast::ItemStruct(_, ref generics) | - ast::ItemTrait(ref generics, _, _, _) => { + ast::ItemTrait(_, ref generics, _, _, _) => { for (i, p) in generics.lifetimes.iter().enumerate() { let id = p.lifetime.id; self.add_inferred(item.id, RegionParam, TypeSpace, i, id); diff --git a/src/librustdoc/clean/inline.rs b/src/librustdoc/clean/inline.rs index 75cf0c7a26b..a7d7c520755 100644 --- a/src/librustdoc/clean/inline.rs +++ b/src/librustdoc/clean/inline.rs @@ -161,6 +161,7 @@ pub fn build_external_trait(cx: &DocContext, tcx: &ty::ctxt, let trait_def = ty::lookup_trait_def(tcx, did); let (bounds, default_unbound) = trait_def.bounds.clean(cx); clean::Trait { + unsafety: def.unsafety, generics: (&def.generics, subst::TypeSpace).clean(cx), items: items.collect(), bounds: bounds, diff --git a/src/librustdoc/clean/mod.rs b/src/librustdoc/clean/mod.rs index 1d0929746c2..92184ce93de 100644 --- a/src/librustdoc/clean/mod.rs +++ b/src/librustdoc/clean/mod.rs @@ -974,6 +974,7 @@ impl Clean for ast::FunctionRetTy { #[deriving(Clone, Encodable, Decodable)] pub struct Trait { + pub unsafety: ast::Unsafety, pub items: Vec, pub generics: Generics, pub bounds: Vec, @@ -991,6 +992,7 @@ impl Clean for doctree::Trait { visibility: self.vis.clean(cx), stability: self.stab.clean(cx), inner: TraitItem(Trait { + unsafety: self.unsafety, items: self.items.clean(cx), generics: self.generics.clean(cx), bounds: self.bounds.clean(cx), diff --git a/src/librustdoc/doctree.rs b/src/librustdoc/doctree.rs index a25d4352430..79f04e91260 100644 --- a/src/librustdoc/doctree.rs +++ b/src/librustdoc/doctree.rs @@ -170,6 +170,7 @@ pub struct Constant { } pub struct Trait { + pub unsafety: ast::Unsafety, pub name: Ident, pub items: Vec, //should be TraitItem pub generics: ast::Generics, diff --git a/src/librustdoc/html/render.rs b/src/librustdoc/html/render.rs index 54b7ead5469..1977b6320d0 100644 --- a/src/librustdoc/html/render.rs +++ b/src/librustdoc/html/render.rs @@ -1693,8 +1693,9 @@ fn item_trait(w: &mut fmt::Formatter, cx: &Context, it: &clean::Item, } // Output the trait definition - try!(write!(w, "
{}trait {}{}{}{} ",
+    try!(write!(w, "
{}{}trait {}{}{}{} ",
                   VisSpace(it.visibility),
+                  UnsafetySpace(t.unsafety),
                   it.name.as_ref().unwrap().as_slice(),
                   t.generics,
                   bounds,
diff --git a/src/librustdoc/visit_ast.rs b/src/librustdoc/visit_ast.rs
index 1706df10d9a..f94e647b1cf 100644
--- a/src/librustdoc/visit_ast.rs
+++ b/src/librustdoc/visit_ast.rs
@@ -322,8 +322,9 @@ impl<'a, 'tcx> RustdocVisitor<'a, 'tcx> {
                 };
                 om.constants.push(s);
             },
-            ast::ItemTrait(ref gen, ref def_ub, ref b, ref items) => {
+            ast::ItemTrait(unsafety, ref gen, ref def_ub, ref b, ref items) => {
                 let t = Trait {
+                    unsafety: unsafety,
                     name: name,
                     items: items.clone(),
                     generics: gen.clone(),
diff --git a/src/libsyntax/ast.rs b/src/libsyntax/ast.rs
index 812b1baa8f7..1cc6b6feee8 100644
--- a/src/libsyntax/ast.rs
+++ b/src/libsyntax/ast.rs
@@ -1611,7 +1611,8 @@ pub enum Item_ {
     ItemEnum(EnumDef, Generics),
     ItemStruct(P, Generics),
     /// Represents a Trait Declaration
-    ItemTrait(Generics,
+    ItemTrait(Unsafety,
+              Generics,
               Option, // (optional) default bound not required for Self.
                                 // Currently, only Sized makes sense here.
               TyParamBounds,
diff --git a/src/libsyntax/ast_map/mod.rs b/src/libsyntax/ast_map/mod.rs
index 6f1d2d39b30..a2cdc4d2fbc 100644
--- a/src/libsyntax/ast_map/mod.rs
+++ b/src/libsyntax/ast_map/mod.rs
@@ -786,7 +786,7 @@ impl<'ast> Visitor<'ast> for NodeCollector<'ast> {
                     None => {}
                 }
             }
-            ItemTrait(_, _, ref bounds, ref trait_items) => {
+            ItemTrait(_, _, _, ref bounds, ref trait_items) => {
                 for b in bounds.iter() {
                     if let TraitTyParamBound(ref t) = *b {
                         self.insert(t.trait_ref.ref_id, NodeItem(i));
diff --git a/src/libsyntax/config.rs b/src/libsyntax/config.rs
index 87426dce918..ee651592117 100644
--- a/src/libsyntax/config.rs
+++ b/src/libsyntax/config.rs
@@ -139,11 +139,11 @@ fn fold_item_underscore(cx: &mut Context, item: ast::Item_) -> ast::Item_
                                        .collect();
             ast::ItemImpl(a, b, c, impl_items)
         }
-        ast::ItemTrait(a, b, c, methods) => {
+        ast::ItemTrait(u, a, b, c, methods) => {
             let methods = methods.into_iter()
                                  .filter(|m| trait_method_in_cfg(cx, m))
                                  .collect();
-            ast::ItemTrait(a, b, c, methods)
+            ast::ItemTrait(u, a, b, c, methods)
         }
         ast::ItemStruct(def, generics) => {
             ast::ItemStruct(fold_struct(cx, def), generics)
diff --git a/src/libsyntax/fold.rs b/src/libsyntax/fold.rs
index c2c77e5a16c..daed014f4eb 100644
--- a/src/libsyntax/fold.rs
+++ b/src/libsyntax/fold.rs
@@ -1035,7 +1035,7 @@ pub fn noop_fold_item_underscore(i: Item_, folder: &mut T) -> Item_ {
                      folder.fold_ty(ty),
                      new_impl_items)
         }
-        ItemTrait(generics, unbound, bounds, methods) => {
+        ItemTrait(unsafety, generics, unbound, bounds, methods) => {
             let bounds = folder.fold_bounds(bounds);
             let methods = methods.into_iter().flat_map(|method| {
                 let r = match method {
@@ -1063,7 +1063,8 @@ pub fn noop_fold_item_underscore(i: Item_, folder: &mut T) -> Item_ {
                 };
                 r
             }).collect();
-            ItemTrait(folder.fold_generics(generics),
+            ItemTrait(unsafety,
+                      folder.fold_generics(generics),
                       unbound,
                       bounds,
                       methods)
diff --git a/src/libsyntax/parse/parser.rs b/src/libsyntax/parse/parser.rs
index cc96d45a1c8..b2c30797cac 100644
--- a/src/libsyntax/parse/parser.rs
+++ b/src/libsyntax/parse/parser.rs
@@ -4628,7 +4628,7 @@ impl<'a> Parser<'a> {
     }
 
     /// Parse trait Foo { ... }
-    fn parse_item_trait(&mut self) -> ItemInfo {
+    fn parse_item_trait(&mut self, unsafety: Unsafety) -> ItemInfo {
         let ident = self.parse_ident();
         let mut tps = self.parse_generics();
         let sized = self.parse_for_sized();
@@ -4639,7 +4639,7 @@ impl<'a> Parser<'a> {
         self.parse_where_clause(&mut tps);
 
         let meths = self.parse_trait_items();
-        (ident, ItemTrait(tps, sized, bounds, meths), None)
+        (ident, ItemTrait(unsafety, tps, sized, bounds, meths), None)
     }
 
     fn parse_impl_items(&mut self) -> (Vec, Vec) {
@@ -5539,6 +5539,23 @@ impl<'a> Parser<'a> {
                                     maybe_append(attrs, extra_attrs));
             return IoviItem(item);
         }
+        if self.token.is_keyword(keywords::Unsafe) &&
+            self.look_ahead(1u, |t| t.is_keyword(keywords::Trait))
+        {
+            // UNSAFE TRAIT ITEM
+            self.expect_keyword(keywords::Unsafe);
+            self.expect_keyword(keywords::Trait);
+            let (ident, item_, extra_attrs) =
+                self.parse_item_trait(ast::Unsafety::Unsafe);
+            let last_span = self.last_span;
+            let item = self.mk_item(lo,
+                                    last_span.hi,
+                                    ident,
+                                    item_,
+                                    visibility,
+                                    maybe_append(attrs, extra_attrs));
+            return IoviItem(item);
+        }
         if self.token.is_keyword(keywords::Fn) &&
                 self.look_ahead(1, |f| !Parser::fn_expr_lookahead(f)) {
             // FUNCTION ITEM
@@ -5614,7 +5631,8 @@ impl<'a> Parser<'a> {
         }
         if self.eat_keyword(keywords::Trait) {
             // TRAIT ITEM
-            let (ident, item_, extra_attrs) = self.parse_item_trait();
+            let (ident, item_, extra_attrs) =
+                self.parse_item_trait(ast::Unsafety::Normal);
             let last_span = self.last_span;
             let item = self.mk_item(lo,
                                     last_span.hi,
diff --git a/src/libsyntax/print/pprust.rs b/src/libsyntax/print/pprust.rs
index 53399aba99a..037118b145f 100644
--- a/src/libsyntax/print/pprust.rs
+++ b/src/libsyntax/print/pprust.rs
@@ -955,9 +955,11 @@ impl<'a> State<'a> {
                 }
                 try!(self.bclose(item.span));
             }
-            ast::ItemTrait(ref generics, ref unbound, ref bounds, ref methods) => {
-                try!(self.head(visibility_qualified(item.vis,
-                                                    "trait").as_slice()));
+            ast::ItemTrait(unsafety, ref generics, ref unbound, ref bounds, ref methods) => {
+                try!(self.head(""));
+                try!(self.print_visibility(item.vis));
+                try!(self.print_unsafety(unsafety));
+                try!(self.word_nbsp("trait"));
                 try!(self.print_ident(item.ident));
                 try!(self.print_generics(generics));
                 if let &Some(ref tref) = unbound {
diff --git a/src/libsyntax/visit.rs b/src/libsyntax/visit.rs
index 6eedb77889a..7bb79a15f45 100644
--- a/src/libsyntax/visit.rs
+++ b/src/libsyntax/visit.rs
@@ -311,7 +311,7 @@ pub fn walk_item<'v, V: Visitor<'v>>(visitor: &mut V, item: &'v Item) {
                                      generics,
                                      item.id)
         }
-        ItemTrait(ref generics, _, ref bounds, ref methods) => {
+        ItemTrait(_, ref generics, _, ref bounds, ref methods) => {
             visitor.visit_generics(generics);
             walk_ty_param_bounds_helper(visitor, bounds);
             for method in methods.iter() {
diff --git a/src/test/pretty/trait-safety.rs b/src/test/pretty/trait-safety.rs
new file mode 100644
index 00000000000..42e578482e6
--- /dev/null
+++ b/src/test/pretty/trait-safety.rs
@@ -0,0 +1,21 @@
+// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0  or the MIT license
+// , at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+// pp-exact
+
+unsafe trait UnsafeTrait {
+    fn foo(&self);
+}
+
+pub unsafe trait PubUnsafeTrait {
+    fn foo(&self);
+}
+
+fn main() { }