rustdoc: incorporate stability index throughout

This commit hooks rustdoc into the stability index infrastructure in two
ways:

1. It looks up stability levels via the index, rather than by manual
attributes.

2. It adds stability level information throughout rustdoc output, rather
than just at the top header. In particular, a stability color (with
mouseover text) appears next to essentially every item that appears
in rustdoc's HTML output.

Along the way, the stability index code has been lightly refactored.

src/librustc/lint/builtin.rs

@@ -30,7 +30,7 @@ use middle::def::*;
 use middle::trans::adt; // for `adt::is_ffi_safe`
 use middle::typeck::astconv::ast_ty_to_ty;
 use middle::typeck::infer;
-use middle::{typeck, ty, def, pat_util};
+use middle::{typeck, ty, def, pat_util, stability};
 use util::ppaux::{ty_to_str};
 use util::nodemap::NodeSet;
 use lint::{Context, LintPass, LintArray};
@@ -1426,11 +1426,7 @@ impl LintPass for Stability {
                     Some(method) => {
                         match method.origin {
                             typeck::MethodStatic(def_id) => {
-                                // If this implements a trait method, get def_id
-                                // of the method inside trait definition.
-                                // Otherwise, use the current def_id (which refers
-                                // to the method inside impl).
-                                ty::trait_method_of_method(cx.tcx, def_id).unwrap_or(def_id)
+                                def_id
                             }
                             typeck::MethodParam(typeck::MethodParam {
                                 trait_id: trait_id,
@@ -1454,8 +1450,7 @@ impl LintPass for Stability {
         // check anything for crate-local usage.
         if ast_util::is_local(id) { return }
 
-        let stability = cx.tcx.stability.borrow_mut().lookup(&cx.tcx.sess.cstore, id);
-
+        let stability = stability::lookup(cx.tcx, id);
         let (lint, label) = match stability {
             // no stability attributes == Unstable
             None => (UNSTABLE, "unmarked"),

src/librustc/metadata/encoder.rs

@@ -24,6 +24,7 @@ use middle::ty::{node_id_to_type, lookup_item_type};
 use middle::astencode;
 use middle::ty;
 use middle::typeck;
+use middle::stability;
 use middle;
 use util::nodemap::{NodeMap, NodeSet};
 
@@ -328,7 +329,7 @@ fn encode_enum_variant_info(ecx: &EncodeContext,
         encode_visibility(ebml_w, variant.node.vis);
         encode_attributes(ebml_w, variant.node.attrs.as_slice());
 
-        let stab = ecx.tcx.stability.borrow().lookup_local(variant.node.id);
+        let stab = stability::lookup(ecx.tcx, ast_util::local_def(variant.node.id));
         encode_stability(ebml_w, stab);
 
         match variant.node.kind {
@@ -592,7 +593,9 @@ fn encode_info_for_mod(ecx: &EncodeContext,
 
     encode_path(ebml_w, path.clone());
     encode_visibility(ebml_w, vis);
-    encode_stability(ebml_w, ecx.tcx.stability.borrow().lookup_local(id));
+
+    let stab = stability::lookup(ecx.tcx, ast_util::local_def(id));
+    encode_stability(ebml_w, stab);
 
     // Encode the reexports of this module, if this module is public.
     if vis == Public {
@@ -722,7 +725,8 @@ fn encode_info_for_struct_ctor(ecx: &EncodeContext,
         encode_symbol(ecx, ebml_w, ctor_id);
     }
 
-    encode_stability(ebml_w, ecx.tcx.stability.borrow().lookup_local(ctor_id));
+    let stab = stability::lookup(ecx.tcx, ast_util::local_def(ctor_id));
+    encode_stability(ebml_w, stab);
 
     // indicate that this is a tuple struct ctor, because downstream users will normally want
     // the tuple struct definition, but without this there is no way for them to tell that
@@ -768,7 +772,7 @@ fn encode_info_for_method(ecx: &EncodeContext,
     encode_method_ty_fields(ecx, ebml_w, m);
     encode_parent_item(ebml_w, local_def(parent_id));
 
-    let stab = ecx.tcx.stability.borrow().lookup_local(m.def_id.node);
+    let stab = stability::lookup(ecx.tcx, m.def_id);
     encode_stability(ebml_w, stab);
 
     // The type for methods gets encoded twice, which is unfortunate.
@@ -915,10 +919,10 @@ fn encode_info_for_item(ecx: &EncodeContext,
     }
 
     debug!("encoding info for item at {}",
-           ecx.tcx.sess.codemap().span_to_str(item.span));
+           tcx.sess.codemap().span_to_str(item.span));
 
     let def_id = local_def(item.id);
-    let stab = tcx.stability.borrow().lookup_local(item.id);
+    let stab = stability::lookup(tcx, ast_util::local_def(item.id));
 
     match item.node {
       ItemStatic(_, m, _) => {
@@ -1206,7 +1210,7 @@ fn encode_info_for_item(ecx: &EncodeContext,
             encode_method_ty_fields(ecx, ebml_w, &*method_ty);
             encode_parent_item(ebml_w, def_id);
 
-            let stab = tcx.stability.borrow().lookup_local(method_def_id.node);
+            let stab = stability::lookup(tcx, method_def_id);
             encode_stability(ebml_w, stab);
 
             let elem = ast_map::PathName(method_ty.ident.name);

src/librustc/middle/stability.rs

@@ -20,7 +20,8 @@ use syntax::ast::{Generics, StructDef, Ident};
 use syntax::ast_util::is_local;
 use syntax::attr::Stability;
 use syntax::visit::{FnKind, FkMethod, Visitor};
-use metadata::{cstore, csearch};
+use middle::ty;
+use metadata::csearch;
 
 /// A stability index, giving the stability level for items and methods.
 pub struct Index {
@@ -105,21 +106,24 @@ impl Index {
                           attr::find_stability(krate.attrs.as_slice()));
         annotator.index
     }
+}
 
-    /// Lookup the stability for a node, loading external crate
-    /// metadata as necessary.
-    pub fn lookup(&mut self, cstore: &cstore::CStore, id: DefId) -> Option<Stability> {
-        if is_local(id) {
-            self.lookup_local(id.node)
-        } else {
-            let stab = csearch::get_stability(cstore, id);
-            self.extern_cache.insert(id, stab.clone());
+/// Lookup the stability for a node, loading external crate
+/// metadata as necessary.
+pub fn lookup(tcx: &ty::ctxt,  id: DefId) -> Option<Stability> {
+    // is this definition the implementation of a trait method?
+    match ty::trait_method_of_method(tcx, id) {
+        Some(trait_method_id) if trait_method_id != id => {
+            lookup(tcx, trait_method_id)
+        }
+        _ if is_local(id) => {
+            tcx.stability.borrow().local.find_copy(&id.node)
+        }
+        _ => {
+            let stab = csearch::get_stability(&tcx.sess.cstore, id);
+            let mut index = tcx.stability.borrow_mut();
+            (*index).extern_cache.insert(id, stab.clone());
             stab
         }
     }
-
-    /// Lookup the stability for a local node without loading any external crates
-    pub fn lookup_local(&self, id: NodeId) -> Option<Stability> {
-        self.local.find_copy(&id)
-    }
 }

src/librustdoc/clean/inline.rs

@@ -18,6 +18,7 @@ use rustc::metadata::csearch;
 use rustc::metadata::decoder;
 use rustc::middle::def;
 use rustc::middle::ty;
+use rustc::middle::stability;
 
 use core;
 use doctree;
@@ -102,6 +103,7 @@ fn try_inline_def(cx: &core::DocContext,
         attrs: load_attrs(tcx, did),
         inner: inner,
         visibility: Some(ast::Public),
+        stability: stability::lookup(tcx, did).clean(),
         def_id: did,
     });
     Some(ret)
@@ -317,6 +319,7 @@ fn build_impl(cx: &core::DocContext,
         name: None,
         attrs: attrs,
         visibility: Some(ast::Inherited),
+        stability: stability::lookup(tcx, did).clean(),
         def_id: did,
     })
 }