expose #[target_feature] attributes in rustdoc

src/librustdoc/clean/cfg.rs

@@ -138,7 +138,7 @@ impl Cfg {
 
  /// Renders the configuration for human display, as a short HTML description.
  pub(crate) fn render_short_html(&self) -> String {
- let mut msg = Html(self).to_string();
+ let mut msg = ShortHtml(self).to_string();
  if self.should_capitalize_first_letter() {
  if let Some(i) = msg.find(|c: char| c.is_ascii_alphanumeric()) {
  msg[i .. i+1].make_ascii_uppercase();
@@ -149,7 +149,13 @@ impl Cfg {
 
  /// Renders the configuration for long display, as a long HTML description.
  pub(crate) fn render_long_html(&self) -> String {
- let mut msg = format!("This is supported on <strong>{}</strong>", Html(self));
+ let on = if self.should_use_with_in_description() {
+ "with"
+ } else {
+ "on"
+ };
+
+ let mut msg = format!("This is supported {} <strong>{}</strong>", on, Html(self));
  if self.should_append_only_to_description() {
  msg.push_str(" only");
  }
@@ -180,6 +186,13 @@ impl Cfg {
  }
  }
  }
+
+ fn should_use_with_in_description(&self) -> bool {
+ match *self {
+ Cfg::Cfg(ref name, _) if name == &"target_feature" => true,
+ _ => false,
+ }
+ }
 }
 
 impl ops::Not for Cfg {
@@ -376,6 +389,8 @@ impl<'a> fmt::Display for Html<'a> {
  },
  ("target_endian", Some(endian)) => return write!(fmt, "{}-endian", endian),
  ("target_pointer_width", Some(bits)) => return write!(fmt, "{}-bit", bits),
+ ("target_feature", Some(feat)) =>
+ return write!(fmt, "target feature <code>{}</code>", feat),
  _ => "",
  };
  if !human_readable.is_empty() {
@@ -390,6 +405,19 @@ impl<'a> fmt::Display for Html<'a> {
  }
 }
 
+struct ShortHtml<'a>(&'a Cfg);
+
+impl<'a> fmt::Display for ShortHtml<'a> {
+ fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
+ match *self.0 {
+ Cfg::Cfg(ref name, Some(ref vendor)) if name == &"target_feature" => {
+ write!(fmt, "<code>{}</code>", vendor)
+ },
+ ref cfg => write!(fmt, "{}", Html(cfg)),
+ }
+ }
+}
+
 #[cfg(test)]
 mod test {
  use super::Cfg;
@@ -824,6 +852,10 @@ mod test {
  ).render_short_html(),
  "(Debug-assertions enabled or Windows) and Unix"
  );
+ assert_eq!(
+ name_value_cfg("target_feature", "sse2").render_short_html(),
+ "<code>sse2</code>"
+ );
  })
  }
 
@@ -898,6 +930,10 @@ mod test {
  "This is supported on <strong>(debug-assertions enabled or Windows) and Unix\
  </strong> only."
  );
+ assert_eq!(
+ name_value_cfg("target_feature", "sse2").render_long_html(),
+ "This is supported with <strong>target feature <code>sse2</code></strong> only."
+ );
  })
  }
 }

src/librustdoc/clean/mod.rs

@@ -828,6 +828,19 @@ impl Attributes {
  })
  }).collect();
 
+ // treat #[target_feature(enable = "feat")] attributes as if they were
+ // #[doc(cfg(target_feature = "feat"))] attributes as well
+ for attr in attrs.lists("target_feature") {
+ if attr.check_name("enable") {
+ if let Some(feat) = attr.value_str() {
+ let meta = attr::mk_name_value_item_str("target_feature".into(), feat);
+ if let Ok(feat_cfg) = Cfg::parse(&meta) {
+ cfg &= feat_cfg;
+ }
+ }
+ }
+ }
+
  Attributes {
  doc_strings,
  other_attrs,