rustdoc: Render stability attributes

Closes #8965

Author: alexcrichton

src/librustdoc/clean.rs

@@ -16,6 +16,7 @@ use its = syntax::parse::token::ident_to_str;
 use syntax;
 use syntax::ast;
 use syntax::ast_util;
+use syntax::attr;
 use syntax::attr::AttributeMethods;
 
 use std;
@@ -206,6 +207,25 @@ impl Clean<Attribute> for ast::Attribute {
     }
 }
 
+// This is a rough approximation that gets us what we want.
+impl<'self> attr::AttrMetaMethods for &'self Attribute {
+    fn name(&self) -> @str {
+        match **self {
+            Word(ref n) | List(ref n, _) | NameValue(ref n, _) =>
+                n.to_managed()
+        }
+    }
+
+    fn value_str(&self) -> Option<@str> {
+        match **self {
+            NameValue(_, ref v) => Some(v.to_managed()),
+            _ => None,
+        }
+    }
+    fn meta_item_list<'a>(&'a self) -> Option<&'a [@ast::MetaItem]> { None }
+    fn name_str_pair(&self) -> Option<(@str, @str)> { None }
+}
+
 #[deriving(Clone, Encodable, Decodable)]
 pub struct TyParam {
     name: ~str,

src/librustdoc/html/render.rs

@@ -28,6 +28,7 @@ use extra::json::ToJson;
 use extra::sort;
 
 use syntax::ast;
+use syntax::attr;
 
 use clean;
 use doctree;
@@ -568,6 +569,18 @@ impl<'self> Item<'self> {
 
 impl<'self> fmt::Default for Item<'self> {
     fn fmt(it: &Item<'self>, fmt: &mut fmt::Formatter) {
+        match attr::find_stability(it.item.attrs.iter()) {
+            Some(stability) => {
+                write!(fmt.buf,
+                       "<a class='stability {lvl}' title='{reason}'>{lvl}</a>",
+                       lvl = stability.level.to_str(),
+                       reason = match stability.text {
+                           Some(s) => s, None => @"",
+                       });
+            }
+            None => {}
+        }
+
         // Write the breadcrumb trail header for the top
         write!(fmt.buf, "<h1 class='fqn'>");
         match it.item.inner {

src/librustdoc/html/static/main.css

@@ -269,3 +269,18 @@ a {
     float: left;
     padding: 20px;
 }
+
+.stability {
+    border-left: 5px solid #000;
+    border-radius: 3px;
+    padding: 0 3px;
+    float: right;
+    background: #fff;
+    text-transform: lowercase;
+}
+.stability.Deprecated { border-color: #D60027; color: #880017; }
+.stability.Experimental { border-color: #EC5315; color: #a53c0e; }
+.stability.Unstable { border-color: #FFD700; color: #b39800; }
+.stability.Stable { border-color: #AEC516; color: #7c8b10; }
+.stability.Frozen { border-color: #009431; color: #007726; }
+.stability.Locked { border-color: #0084B6; color: #00668c; }

src/libsyntax/attr.rs

@@ -320,7 +320,7 @@ pub struct Stability {
 }
 
 /// The available stability levels.
-#[deriving(Eq,Ord,Clone)]
+#[deriving(Eq,Ord,Clone,ToStr)]
 pub enum StabilityLevel {
     Deprecated,
     Experimental,