Auto merge of #37824 - jseyfried:symbols, r=eddyb

Clean up `ast::Attribute`, `ast::CrateConfig`, and string interning

This PR
 - removes `ast::Attribute_` (changing `Attribute` from `Spanned<Attribute_>` to a struct),
 - moves a `MetaItem`'s name from the `MetaItemKind` variants to a field of `MetaItem`,
 - avoids needlessly wrapping `ast::MetaItem` with `P`,
 - moves string interning into `syntax::symbol` (`ast::Name` is a reexport of `symbol::Symbol` for now),
 - replaces `InternedString` with `Symbol` in the AST, HIR, and various other places, and
 - refactors `ast::CrateConfig` from a `Vec` to a `HashSet`.

r? @eddyb

1 files changed, 6 insertions, 5 deletions

diff --git a/src/libsyntax_ext/lib.rs b/src/libsyntax_ext/lib.rs
index 1ebac19b4f0..e83fd55cd71 100644
--- a/src/libsyntax_ext/lib.rs
+++ b/src/libsyntax_ext/lib.rs
@@ -53,7 +53,7 @@ use std::rc::Rc;
 use syntax::ast;
 use syntax::ext::base::{MacroExpanderFn, NormalTT, IdentTT, MultiModifier, NamedSyntaxExtension};
 use syntax::ext::tt::macro_rules::MacroRulesExpander;
-use syntax::parse::token::intern;
+use syntax::symbol::Symbol;
 
 pub fn register_builtins(resolver: &mut syntax::ext::base::Resolver,
                          user_exts: Vec<NamedSyntaxExtension>,
@@ -62,11 +62,11 @@ pub fn register_builtins(resolver: &mut syntax::ext::base::Resolver,
         resolver.add_ext(ast::Ident::with_empty_ctxt(name), Rc::new(ext));
     };
 
-    register(intern("macro_rules"), IdentTT(Box::new(MacroRulesExpander), None, false));
+    register(Symbol::intern("macro_rules"), IdentTT(Box::new(MacroRulesExpander), None, false));
 
     macro_rules! register {
         ($( $name:ident: $f:expr, )*) => { $(
-            register(intern(stringify!($name)),
+            register(Symbol::intern(stringify!($name)),
                      NormalTT(Box::new($f as MacroExpanderFn), None, false));
         )* }
     }
@@ -112,9 +112,10 @@ pub fn register_builtins(resolver: &mut syntax::ext::base::Resolver,
     }
 
     // format_args uses `unstable` things internally.
-    register(intern("format_args"), NormalTT(Box::new(format::expand_format_args), None, true));
+    register(Symbol::intern("format_args"),
+             NormalTT(Box::new(format::expand_format_args), None, true));
 
-    register(intern("derive"), MultiModifier(Box::new(deriving::expand_derive)));
+    register(Symbol::intern("derive"), MultiModifier(Box::new(deriving::expand_derive)));
 
     for (name, ext) in user_exts {
         register(name, ext);