Auto merge of #40867 - alexcrichton:rollup, r=alexcrichton

Rollup of 19 pull requests

- Successful merges: #40317, #40516, #40524, #40606, #40683, #40751, #40778, #40813, #40818, #40819, #40824, #40828, #40832, #40833, #40837, #40849, #40852, #40853, #40865
- Failed merges:

6 files changed, 50 insertions, 15 deletions

diff --git a/src/libsyntax/ext/placeholders.rs b/src/libsyntax/ext/placeholders.rs
index f0e328a551d..2d0994a7b78 100644
--- a/src/libsyntax/ext/placeholders.rs
+++ b/src/libsyntax/ext/placeholders.rs
@@ -106,8 +106,8 @@ impl<'a, 'b> PlaceholderExpander<'a, 'b> {
 impl<'a, 'b> Folder for PlaceholderExpander<'a, 'b> {
     fn fold_item(&mut self, item: P<ast::Item>) -> SmallVector<P<ast::Item>> {
         match item.node {
-            ast::ItemKind::Mac(ref mac) if !mac.node.path.segments.is_empty() => {}
             ast::ItemKind::Mac(_) => return self.remove(item.id).make_items(),
+            ast::ItemKind::MacroDef(_) => return SmallVector::one(item),
             _ => {}
         }
 
diff --git a/src/libsyntax/ext/tt/macro_rules.rs b/src/libsyntax/ext/tt/macro_rules.rs
index 021c5398a42..66f5520b882 100644
--- a/src/libsyntax/ext/tt/macro_rules.rs
+++ b/src/libsyntax/ext/tt/macro_rules.rs
@@ -119,7 +119,7 @@ fn generic_extension<'cx>(cx: &'cx ExtCtxt,
                 };
                 let mut p = Parser::new(cx.parse_sess(), tts, Some(directory), false);
                 p.root_module_name = cx.current_expansion.module.mod_path.last()
-                    .map(|id| (*id.name.as_str()).to_owned());
+                    .map(|id| id.name.as_str().to_string());
 
                 p.check_unknown_macro_variable();
                 // Let the context choose how to interpret the result.
diff --git a/src/libsyntax/feature_gate.rs b/src/libsyntax/feature_gate.rs
index 7af432176cf..9d280a413e6 100644
--- a/src/libsyntax/feature_gate.rs
+++ b/src/libsyntax/feature_gate.rs
@@ -818,7 +818,7 @@ pub struct GatedCfg {
 
 impl GatedCfg {
     pub fn gate(cfg: &ast::MetaItem) -> Option<GatedCfg> {
-        let name = &*cfg.name().as_str();
+        let name = cfg.name().as_str();
         GATED_CFGS.iter()
                   .position(|info| info.0 == name)
                   .map(|idx| {
@@ -865,8 +865,7 @@ macro_rules! gate_feature {
 impl<'a> Context<'a> {
     fn check_attribute(&self, attr: &ast::Attribute, is_macro: bool) {
         debug!("check_attribute(attr = {:?})", attr);
-        let name = unwrap_or!(attr.name(), return);
-
+        let name = unwrap_or!(attr.name(), return).as_str();
         for &(n, ty, ref gateage) in BUILTIN_ATTRIBUTES {
             if name == n {
                 if let &Gated(_, ref name, ref desc, ref has_feature) = gateage {
@@ -885,12 +884,12 @@ impl<'a> Context<'a> {
                 return;
             }
         }
-        if name.as_str().starts_with("rustc_") {
+        if name.starts_with("rustc_") {
             gate_feature!(self, rustc_attrs, attr.span,
                           "unless otherwise specified, attributes \
                            with the prefix `rustc_` \
                            are reserved for internal compiler diagnostics");
-        } else if name.as_str().starts_with("derive_") {
+        } else if name.starts_with("derive_") {
             gate_feature!(self, custom_derive, attr.span, EXPLAIN_DERIVE_UNDERSCORE);
         } else if !attr::is_known(attr) {
             // Only run the custom attribute lint during regular
diff --git a/src/libsyntax/parse/parser.rs b/src/libsyntax/parse/parser.rs
index 649e9059934..43a9d8c5f78 100644
--- a/src/libsyntax/parse/parser.rs
+++ b/src/libsyntax/parse/parser.rs
@@ -5151,15 +5151,15 @@ impl<'a> Parser<'a> {
 
     fn push_directory(&mut self, id: Ident, attrs: &[Attribute]) {
         if let Some(path) = attr::first_attr_value_str_by_name(attrs, "path") {
-            self.directory.path.push(&*path.as_str());
+            self.directory.path.push(&path.as_str());
             self.directory.ownership = DirectoryOwnership::Owned;
         } else {
-            self.directory.path.push(&*id.name.as_str());
+            self.directory.path.push(&id.name.as_str());
         }
     }
 
     pub fn submod_path_from_attr(attrs: &[ast::Attribute], dir_path: &Path) -> Option<PathBuf> {
-        attr::first_attr_value_str_by_name(attrs, "path").map(|d| dir_path.join(&*d.as_str()))
+        attr::first_attr_value_str_by_name(attrs, "path").map(|d| dir_path.join(&d.as_str()))
     }
 
     /// Returns either a path to a module, or .
diff --git a/src/libsyntax/symbol.rs b/src/libsyntax/symbol.rs
index 6642c60d256..2acbeee426b 100644
--- a/src/libsyntax/symbol.rs
+++ b/src/libsyntax/symbol.rs
@@ -72,9 +72,9 @@ impl Decodable for Symbol {
     }
 }
 
-impl<'a> PartialEq<&'a str> for Symbol {
-    fn eq(&self, other: &&str) -> bool {
-        *self.as_str() == **other
+impl<T: ::std::ops::Deref<Target=str>> PartialEq<T> for Symbol {
+    fn eq(&self, other: &T) -> bool {
+        self.as_str() == other.deref()
     }
 }
 
@@ -244,11 +244,47 @@ fn with_interner<T, F: FnOnce(&mut Interner) -> T>(f: F) -> T {
 /// destroyed. In particular, they must not access string contents. This can
 /// be fixed in the future by just leaking all strings until thread death
 /// somehow.
-#[derive(Clone, PartialEq, Hash, PartialOrd, Eq, Ord)]
+#[derive(Clone, Hash, PartialOrd, Eq, Ord)]
 pub struct InternedString {
     string: &'static str,
 }
 
+impl<U: ?Sized> ::std::convert::AsRef<U> for InternedString where str: ::std::convert::AsRef<U> {
+    fn as_ref(&self) -> &U {
+        self.string.as_ref()
+    }
+}
+
+impl<T: ::std::ops::Deref<Target = str>> ::std::cmp::PartialEq<T> for InternedString {
+    fn eq(&self, other: &T) -> bool {
+        self.string == other.deref()
+    }
+}
+
+impl ::std::cmp::PartialEq<InternedString> for str {
+    fn eq(&self, other: &InternedString) -> bool {
+        self == other.string
+    }
+}
+
+impl<'a> ::std::cmp::PartialEq<InternedString> for &'a str {
+    fn eq(&self, other: &InternedString) -> bool {
+        *self == other.string
+    }
+}
+
+impl ::std::cmp::PartialEq<InternedString> for String {
+    fn eq(&self, other: &InternedString) -> bool {
+        self == other.string
+    }
+}
+
+impl<'a> ::std::cmp::PartialEq<InternedString> for &'a String {
+    fn eq(&self, other: &InternedString) -> bool {
+        *self == other.string
+    }
+}
+
 impl !Send for InternedString { }
 
 impl ::std::ops::Deref for InternedString {
diff --git a/src/libsyntax/test.rs b/src/libsyntax/test.rs
index e052d2cda3a..6fb6db9ca02 100644
--- a/src/libsyntax/test.rs
+++ b/src/libsyntax/test.rs
@@ -616,7 +616,7 @@ fn mk_tests(cx: &TestCtxt) -> P<ast::Item> {
 
 fn is_test_crate(krate: &ast::Crate) -> bool {
     match attr::find_crate_name(&krate.attrs) {
-        Some(s) if "test" == &*s.as_str() => true,
+        Some(s) if "test" == s.as_str() => true,
         _ => false
     }
 }