rustdoc: Overhaul stability displays

This commit is an overhaul to how rustdoc deals with stability of the standard
library. The handling has all been revisited with respect to Rust's current
approach to stability in terms of implementation as well as the state of the
standard library today. The high level changes made were:

* Stable items now have no marker by default
* Color-based small stability markers have been removed
* Module listings now fade out unstable/deprecated items slightly
* Trait methods have a separate background color based on stability and also
  list the reason that they are unstable.
* `impl` blocks with stability no longer render at all. This may be re-added
  once the compiler recognizes stability on `impl` blocks.
* `impl` blocks no longer have stability of the methods implemente indicated
* The stability summary has been removed

Closes #15468
Closes #21674
Closes #24201

src/librustdoc/clean/mod.rs

@@ -313,6 +313,22 @@ impl Item {
     pub fn is_fn(&self) -> bool {
         match self.inner { FunctionItem(..) => true, _ => false }
     }
+
+    pub fn stability_class(&self) -> String {
+        match self.stability {
+            Some(ref s) => {
+                let mut base = match s.level {
+                    attr::Unstable => "unstable".to_string(),
+                    attr::Stable => String::new(),
+                };
+                if s.deprecated_since.len() > 0 {
+                    base.push_str(" deprecated");
+                }
+                base
+            }
+            _ => String::new(),
+        }
+    }
 }
 
 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]

src/librustdoc/html/format.rs

@@ -23,10 +23,8 @@ use syntax::ast;
 use syntax::ast_util;
 
 use clean;
-use stability_summary::ModuleSummary;
 use html::item_type::ItemType;
 use html::render;
-use html::escape::Escape;
 use html::render::{cache, CURRENT_LOCATION_KEY};
 
 /// Helper to render an optional visibility with a space after it (if the
@@ -45,10 +43,6 @@ pub struct MutableSpace(pub clean::Mutability);
 /// Similar to VisSpace, but used for mutability
 #[derive(Copy, Clone)]
 pub struct RawMutableSpace(pub clean::Mutability);
-/// Wrapper struct for properly emitting the stability level.
-pub struct Stability<'a>(pub &'a Option<clean::Stability>);
-/// Wrapper struct for emitting the stability level concisely.
-pub struct ConciseStability<'a>(pub &'a Option<clean::Stability>);
 /// Wrapper struct for emitting a where clause from Generics.
 pub struct WhereClause<'a>(pub &'a clean::Generics);
 /// Wrapper struct for emitting type parameter bounds.
@@ -702,119 +696,3 @@ impl fmt::Display for AbiSpace {
         }
     }
 }
-
-impl<'a> fmt::Display for Stability<'a> {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        let Stability(stab) = *self;
-        match *stab {
-            Some(ref stability) => {
-                let lvl = if stability.deprecated_since.is_empty() {
-                    format!("{}", stability.level)
-                } else {
-                    "Deprecated".to_string()
-                };
-                write!(f, "<a class='stability {lvl}' title='{reason}'>{lvl}</a>",
-                       lvl = Escape(&*lvl),
-                       reason = Escape(&*stability.reason))
-            }
-            None => Ok(())
-        }
-    }
-}
-
-impl<'a> fmt::Display for ConciseStability<'a> {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        let ConciseStability(stab) = *self;
-        match *stab {
-            Some(ref stability) => {
-                let lvl = if stability.deprecated_since.is_empty() {
-                    format!("{}", stability.level)
-                } else {
-                    "Deprecated".to_string()
-                };
-                write!(f, "<a class='stability {lvl}' title='{lvl}{colon}{reason}'></a>",
-                       lvl = Escape(&*lvl),
-                       colon = if !stability.reason.is_empty() { ": " } else { "" },
-                       reason = Escape(&*stability.reason))
-            }
-            None => {
-                write!(f, "<a class='stability Unmarked' title='No stability level'></a>")
-            }
-        }
-    }
-}
-
-impl fmt::Display for ModuleSummary {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        fn fmt_inner<'a>(f: &mut fmt::Formatter,
-                         context: &mut Vec<&'a str>,
-                         m: &'a ModuleSummary)
-                     -> fmt::Result {
-            let cnt = m.counts;
-            let tot = cnt.total();
-            if tot == 0 { return Ok(()) }
-
-            context.push(&m.name);
-            let path = context.connect("::");
-
-            try!(write!(f, "<tr>"));
-            try!(write!(f, "<td><a href='{}'>{}</a></td>", {
-                            let mut url = context[1..].to_vec();
-                            url.push("index.html");
-                            url.connect("/")
-                        },
-                        path));
-            try!(write!(f, "<td class='summary-column'>"));
-            try!(write!(f, "<span class='summary Stable' \
-                            style='width: {:.4}%; display: inline-block'>&nbsp</span>",
-                        (100 * cnt.stable) as f64/tot as f64));
-            try!(write!(f, "<span class='summary Unstable' \
-                            style='width: {:.4}%; display: inline-block'>&nbsp</span>",
-                        (100 * cnt.unstable) as f64/tot as f64));
-            try!(write!(f, "<span class='summary Deprecated' \
-                            style='width: {:.4}%; display: inline-block'>&nbsp</span>",
-                        (100 * cnt.deprecated) as f64/tot as f64));
-            try!(write!(f, "<span class='summary Unmarked' \
-                            style='width: {:.4}%; display: inline-block'>&nbsp</span>",
-                        (100 * cnt.unmarked) as f64/tot as f64));
-            try!(write!(f, "</td></tr>"));
-
-            for submodule in &m.submodules {
-                try!(fmt_inner(f, context, submodule));
-            }
-            context.pop();
-            Ok(())
-        }
-
-        let mut context = Vec::new();
-
-        let tot = self.counts.total();
-        let (stable, unstable, deprecated, unmarked) = if tot == 0 {
-            (0, 0, 0, 0)
-        } else {
-            ((100 * self.counts.stable)/tot,
-             (100 * self.counts.unstable)/tot,
-             (100 * self.counts.deprecated)/tot,
-             (100 * self.counts.unmarked)/tot)
-        };
-
-        try!(write!(f,
-r"<h1 class='fqn'>Stability dashboard: crate <a class='mod' href='index.html'>{name}</a></h1>
-This dashboard summarizes the stability levels for all of the public modules of
-the crate, according to the total number of items at each level in the module and
-its children (percentages total for {name}):
-<blockquote>
-<a class='stability Stable'></a> stable ({}%),<br/>
-<a class='stability Unstable'></a> unstable ({}%),<br/>
-<a class='stability Deprecated'></a> deprecated ({}%),<br/>
-<a class='stability Unmarked'></a> unmarked ({}%)
-</blockquote>
-The counts do not include methods or trait
-implementations that are visible only through a re-exported type.",
-stable, unstable, deprecated, unmarked,
-name=self.name));
-        try!(write!(f, "<table>"));
-        try!(fmt_inner(f, &mut context, self));
-        write!(f, "</table>")
-    }
-}