Ungate default type parameters.

These are in scope for 1.0, and this is good to e.g. find as many bugs
as possible.

Author: huonw

src/librustc_driver/driver.rs

@@ -272,7 +272,6 @@ pub fn phase_2_configure_and_expand(sess: &Session,
             }
             let cfg = syntax::ext::expand::ExpansionConfig {
                 crate_name: crate_name.to_string(),
-                deriving_hash_type_parameter: sess.features.borrow().default_type_params,
                 enable_quotes: sess.features.borrow().quote,
                 recursion_limit: sess.recursion_limit.get(),
             };

src/librustc_llvm/lib.rs

@@ -24,6 +24,7 @@
 #![feature(globs)]
 #![feature(link_args)]
 #![feature(unboxed_closures)]
+#![feature(old_orphan_check)]
 
 extern crate libc;
 

src/librustc_resolve/lib.rs

@@ -19,6 +19,7 @@
 #![feature(globs, phase, slicing_syntax)]
 #![feature(rustc_diagnostic_macros)]
 #![feature(associated_types)]
+#![feature(old_orphan_check)]
 
 #[phase(plugin, link)] extern crate log;
 #[phase(plugin, link)] extern crate syntax;

src/librustc_typeck/astconv.rs

@@ -360,14 +360,6 @@ fn create_substs_for_ast_path<'tcx,AC,RS>(
                                            supplied_ty_param_count)[]);
     }
 
-    if supplied_ty_param_count > required_ty_param_count
-        && !this.tcx().sess.features.borrow().default_type_params {
-        span_err!(this.tcx().sess, span, E0108,
-            "default type parameters are experimental and possibly buggy");
-        span_help!(this.tcx().sess, span,
-            "add #![feature(default_type_params)] to the crate attributes to enable");
-    }
-
     let mut substs = Substs::new_type(types, regions);
 
     match self_ty {

src/libsyntax/ext/deriving/hash.rs

@@ -25,20 +25,14 @@ pub fn expand_deriving_hash<F>(cx: &mut ExtCtxt,
     F: FnOnce(P<Item>),
 {
 
-    let (path, generics, args) = if cx.ecfg.deriving_hash_type_parameter {
-        (Path::new_(vec!("std", "hash", "Hash"), None,
-                    vec!(box Literal(Path::new_local("__S"))), true),
-         LifetimeBounds {
-             lifetimes: Vec::new(),
-             bounds: vec!(("__S",
-                           vec!(Path::new(vec!("std", "hash", "Writer"))))),
-         },
-         Path::new_local("__S"))
-    } else {
-        (Path::new(vec!("std", "hash", "Hash")),
-         LifetimeBounds::empty(),
-         Path::new(vec!("std", "hash", "sip", "SipState")))
+    let path = Path::new_(vec!("std", "hash", "Hash"), None,
+                          vec!(box Literal(Path::new_local("__S"))), true);
+    let generics = LifetimeBounds {
+        lifetimes: Vec::new(),
+        bounds: vec!(("__S",
+                      vec!(Path::new(vec!("std", "hash", "Writer"))))),
     };
+    let args = Path::new_local("__S");
     let inline = cx.meta_word(span, InternedString::new("inline"));
     let attrs = vec!(cx.attribute(span, inline));
     let hash_trait_def = TraitDef {

src/libsyntax/ext/expand.rs

@@ -1161,7 +1161,6 @@ fn new_span(cx: &ExtCtxt, sp: Span) -> Span {
 
 pub struct ExpansionConfig {
     pub crate_name: String,
-    pub deriving_hash_type_parameter: bool,
     pub enable_quotes: bool,
     pub recursion_limit: uint,
 }
@@ -1170,7 +1169,6 @@ impl ExpansionConfig {
     pub fn default(crate_name: String) -> ExpansionConfig {
         ExpansionConfig {
             crate_name: crate_name,
-            deriving_hash_type_parameter: false,
             enable_quotes: false,
             recursion_limit: 64,
         }

src/libsyntax/feature_gate.rs

@@ -54,7 +54,7 @@ static KNOWN_FEATURES: &'static [(&'static str, Status)] = &[
     ("lang_items", Active),
 
     ("simd", Active),
-    ("default_type_params", Active),
+    ("default_type_params", Accepted),
     ("quote", Active),
     ("link_llvm_intrinsics", Active),
     ("linkage", Active),
@@ -112,7 +112,6 @@ enum Status {
 /// A set of features to be used by later passes.
 #[derive(Copy)]
 pub struct Features {
-    pub default_type_params: bool,
     pub unboxed_closures: bool,
     pub rustc_diagnostic_macros: bool,
     pub import_shadowing: bool,
@@ -125,7 +124,6 @@ pub struct Features {
 impl Features {
     pub fn new() -> Features {
         Features {
-            default_type_params: false,
             unboxed_closures: false,
             rustc_diagnostic_macros: false,
             import_shadowing: false,
@@ -356,20 +354,6 @@ impl<'a, 'v> Visitor<'v> for PostExpansionVisitor<'a> {
         visit::walk_expr(self, e);
     }
 
-    fn visit_generics(&mut self, generics: &ast::Generics) {
-        for type_parameter in generics.ty_params.iter() {
-            match type_parameter.default {
-                Some(ref ty) => {
-                    self.gate_feature("default_type_params", ty.span,
-                                      "default type parameters are \
-                                       experimental and possibly buggy");
-                }
-                None => {}
-            }
-        }
-        visit::walk_generics(self, generics);
-    }
-
     fn visit_attribute(&mut self, attr: &ast::Attribute) {
         if attr::contains_name(slice::ref_slice(attr), "lang") {
             self.gate_feature("lang_items",
@@ -475,7 +459,6 @@ fn check_crate_inner<F>(cm: &CodeMap, span_handler: &SpanHandler, krate: &ast::C
     check(&mut cx, krate);
 
     (Features {
-        default_type_params: cx.has_feature("default_type_params"),
         unboxed_closures: cx.has_feature("unboxed_closures"),
         rustc_diagnostic_macros: cx.has_feature("rustc_diagnostic_macros"),
         import_shadowing: cx.has_feature("import_shadowing"),