auto merge of #14022 : pcwalton/rust/explicit-self, r=pnkfelix

r? @nikomatsakis

src/librustc/metadata/csearch.rs

@@ -132,7 +132,8 @@ pub fn get_method(tcx: &ty::ctxt, def: ast::DefId) -> ty::Method {
 
 pub fn get_method_name_and_explicit_self(cstore: &cstore::CStore,
                                          def: ast::DefId)
-                                     -> (ast::Ident, ast::ExplicitSelf_)
+                                         -> (ast::Ident,
+                                             ty::ExplicitSelfCategory)
 {
     let cdata = cstore.get_crate_data(def.krate);
     decoder::get_method_name_and_explicit_self(cstore.intr.clone(), &*cdata, def.node)

src/librustc/metadata/decoder.rs

@@ -724,7 +724,7 @@ pub fn get_enum_variants(intr: Rc<IdentInterner>, cdata: Cmd, id: ast::NodeId,
     }).collect()
 }
 
-fn get_explicit_self(item: ebml::Doc) -> ast::ExplicitSelf_ {
+fn get_explicit_self(item: ebml::Doc) -> ty::ExplicitSelfCategory {
     fn get_mutability(ch: u8) -> ast::Mutability {
         match ch as char {
             'i' => ast::MutImmutable,
@@ -738,12 +738,15 @@ fn get_explicit_self(item: ebml::Doc) -> ast::ExplicitSelf_ {
 
     let explicit_self_kind = string.as_bytes()[0];
     match explicit_self_kind as char {
-        's' => ast::SelfStatic,
-        'v' => ast::SelfValue(special_idents::self_),
-        '~' => ast::SelfUniq(special_idents::self_),
+        's' => ty::StaticExplicitSelfCategory,
+        'v' => ty::ByValueExplicitSelfCategory,
+        '~' => ty::ByBoxExplicitSelfCategory,
         // FIXME(#4846) expl. region
-        '&' => ast::SelfRegion(None, get_mutability(string.as_bytes()[1]),
-                               special_idents::self_),
+        '&' => {
+            ty::ByReferenceExplicitSelfCategory(
+                ty::ReEmpty,
+                get_mutability(string.as_bytes()[1]))
+        }
         _ => fail!("unknown self type code: `{}`", explicit_self_kind as char)
     }
 }
@@ -761,11 +764,11 @@ pub fn get_impl_methods(cdata: Cmd, impl_id: ast::NodeId) -> Vec<ast::DefId> {
     methods
 }
 
-pub fn get_method_name_and_explicit_self(
-    intr: Rc<IdentInterner>,
-    cdata: Cmd,
-    id: ast::NodeId) -> (ast::Ident, ast::ExplicitSelf_)
-{
+pub fn get_method_name_and_explicit_self(intr: Rc<IdentInterner>,
+                                         cdata: Cmd,
+                                         id: ast::NodeId)
+                                         -> (ast::Ident,
+                                             ty::ExplicitSelfCategory) {
     let method_doc = lookup_item(id, cdata.data());
     let name = item_name(&*intr, method_doc);
     let explicit_self = get_explicit_self(method_doc);

src/librustc/metadata/encoder.rs

@@ -402,7 +402,7 @@ fn encode_reexported_static_base_methods(ecx: &EncodeContext,
             for base_impl_did in implementations.borrow().iter() {
                 for &method_did in impl_methods.get(base_impl_did).iter() {
                     let m = ty::method(ecx.tcx, method_did);
-                    if m.explicit_self == ast::SelfStatic {
+                    if m.explicit_self == ty::StaticExplicitSelfCategory {
                         encode_reexported_static_method(ebml_w, exp, m.def_id, m.ident);
                     }
                 }
@@ -421,7 +421,7 @@ fn encode_reexported_static_trait_methods(ecx: &EncodeContext,
     match ecx.tcx.trait_methods_cache.borrow().find(&exp.def_id) {
         Some(methods) => {
             for m in methods.iter() {
-                if m.explicit_self == ast::SelfStatic {
+                if m.explicit_self == ty::StaticExplicitSelfCategory {
                     encode_reexported_static_method(ebml_w, exp, m.def_id, m.ident);
                 }
             }
@@ -623,15 +623,22 @@ fn encode_visibility(ebml_w: &mut Encoder, visibility: Visibility) {
     ebml_w.end_tag();
 }
 
-fn encode_explicit_self(ebml_w: &mut Encoder, explicit_self: ast::ExplicitSelf_) {
+fn encode_explicit_self(ebml_w: &mut Encoder,
+                        explicit_self: &ty::ExplicitSelfCategory) {
     ebml_w.start_tag(tag_item_trait_method_explicit_self);
 
     // Encode the base self type.
-    match explicit_self {
-        SelfStatic   => { ebml_w.writer.write(&[ 's' as u8 ]); }
-        SelfValue(_) => { ebml_w.writer.write(&[ 'v' as u8 ]); }
-        SelfUniq(_)  => { ebml_w.writer.write(&[ '~' as u8 ]); }
-        SelfRegion(_, m, _) => {
+    match *explicit_self {
+        ty::StaticExplicitSelfCategory => {
+            ebml_w.writer.write(&[ 's' as u8 ]);
+        }
+        ty::ByValueExplicitSelfCategory => {
+            ebml_w.writer.write(&[ 'v' as u8 ]);
+        }
+        ty::ByBoxExplicitSelfCategory => {
+            ebml_w.writer.write(&[ '~' as u8 ]);
+        }
+        ty::ByReferenceExplicitSelfCategory(_, m) => {
             // FIXME(#4846) encode custom lifetime
             ebml_w.writer.write(&['&' as u8]);
             encode_mutability(ebml_w, m);
@@ -748,10 +755,10 @@ fn encode_method_ty_fields(ecx: &EncodeContext,
                               tag_item_method_tps);
     encode_method_fty(ecx, ebml_w, &method_ty.fty);
     encode_visibility(ebml_w, method_ty.vis);
-    encode_explicit_self(ebml_w, method_ty.explicit_self);
+    encode_explicit_self(ebml_w, &method_ty.explicit_self);
     let fn_style = method_ty.fty.fn_style;
     match method_ty.explicit_self {
-        ast::SelfStatic => {
+        ty::StaticExplicitSelfCategory => {
             encode_family(ebml_w, fn_style_static_method_family(fn_style));
         }
         _ => encode_family(ebml_w, style_fn_family(fn_style))
@@ -1206,7 +1213,7 @@ fn encode_info_for_item(ecx: &EncodeContext,
             encode_path(ebml_w, path.clone().chain(Some(elem).move_iter()));
 
             match method_ty.explicit_self {
-                SelfStatic => {
+                ty::StaticExplicitSelfCategory => {
                     encode_family(ebml_w,
                                   fn_style_static_method_family(
                                       method_ty.fty.fn_style));
@@ -1233,7 +1240,7 @@ fn encode_info_for_item(ecx: &EncodeContext,
                     encode_attributes(ebml_w, m.attrs.as_slice());
                     // If this is a static method, we've already encoded
                     // this.
-                    if method_ty.explicit_self != SelfStatic {
+                    if method_ty.explicit_self != ty::StaticExplicitSelfCategory {
                         // FIXME: I feel like there is something funny going on.
                         let pty = ty::lookup_item_type(tcx, method_def_id);
                         encode_bounds_and_type(ebml_w, ecx, &pty);

src/librustc/middle/region.rs

@@ -314,6 +314,16 @@ impl RegionMaps {
                     self.sub_free_region(sub_fr, super_fr)
                 }
 
+                (ty::ReEarlyBound(param_id_a, param_space_a, index_a, _),
+                 ty::ReEarlyBound(param_id_b, param_space_b, index_b, _)) => {
+                    // This case is used only to make sure that explicitly-
+                    // specified `Self` types match the real self type in
+                    // implementations.
+                    param_id_a == param_id_b &&
+                        param_space_a == param_space_b &&
+                        index_a == index_b
+                }
+
                 _ => {
                     false
                 }

src/librustc/middle/resolve.rs

@@ -11,13 +11,14 @@
 #![allow(non_camel_case_types)]
 
 use driver::session::Session;
+use lint;
 use metadata::csearch;
 use metadata::decoder::{DefLike, DlDef, DlField, DlImpl};
 use middle::def::*;
 use middle::lang_items::LanguageItems;
 use middle::pat_util::pat_bindings;
 use middle::subst::{ParamSpace, FnSpace, TypeSpace};
-use lint;
+use middle::ty::{ExplicitSelfCategory, StaticExplicitSelfCategory};
 use util::nodemap::{NodeMap, DefIdSet, FnvHashMap};
 
 use syntax::ast::*;
@@ -287,6 +288,24 @@ enum ModulePrefixResult {
     PrefixFound(Rc<Module>, uint)
 }
 
+#[deriving(Clone, Eq, PartialEq)]
+enum MethodIsStaticFlag {
+    MethodIsNotStatic,
+    MethodIsStatic,
+}
+
+impl MethodIsStaticFlag {
+    fn from_explicit_self_category(explicit_self_category:
+                                   ExplicitSelfCategory)
+                                   -> MethodIsStaticFlag {
+        if explicit_self_category == StaticExplicitSelfCategory {
+            MethodIsStatic
+        } else {
+            MethodIsNotStatic
+        }
+    }
+}
+
 #[deriving(PartialEq)]
 enum NameSearchType {
     /// We're doing a name search in order to resolve a `use` directive.
@@ -805,7 +824,8 @@ struct Resolver<'a> {
 
     graph_root: NameBindings,
 
-    method_map: RefCell<FnvHashMap<(Name, DefId), ast::ExplicitSelf_>>,
+    method_map: RefCell<FnvHashMap<(Name, DefId), MethodIsStaticFlag>>,
+
     structs: FnvHashMap<DefId, Vec<Name>>,
 
     // The number of imports that are currently unresolved.
@@ -1361,17 +1381,19 @@ impl<'a> Resolver<'a> {
                     let ident = ty_m.ident;
 
                     // Add it as a name in the trait module.
-                    let def = match ty_m.explicit_self.node {
+                    let (def, static_flag) = match ty_m.explicit_self.node {
                         SelfStatic => {
                             // Static methods become `def_static_method`s.
-                            DefStaticMethod(local_def(ty_m.id),
+                            (DefStaticMethod(local_def(ty_m.id),
                                               FromTrait(local_def(item.id)),
-                                              ty_m.fn_style)
+                                              ty_m.fn_style),
+                             MethodIsStatic)
                         }
                         _ => {
                             // Non-static methods become `def_method`s.
-                            DefMethod(local_def(ty_m.id),
-                                       Some(local_def(item.id)))
+                            (DefMethod(local_def(ty_m.id),
+                                       Some(local_def(item.id))),
+                             MethodIsNotStatic)
                         }
                     };
 
@@ -1382,8 +1404,9 @@ impl<'a> Resolver<'a> {
                                        ty_m.span);
                     method_name_bindings.define_value(def, ty_m.span, true);
 
-                    self.method_map.borrow_mut().insert((ident.name, def_id),
-                                                        ty_m.explicit_self.node);
+                    self.method_map
+                        .borrow_mut()
+                        .insert((ident.name, def_id), static_flag);
                 }
 
                 name_bindings.define_type(DefTrait(def_id), sp, is_public);
@@ -1670,7 +1693,11 @@ impl<'a> Resolver<'a> {
                           trait method '{}'",
                          token::get_ident(method_name));
 
-                  self.method_map.borrow_mut().insert((method_name.name, def_id), explicit_self);
+                  self.method_map
+                      .borrow_mut()
+                      .insert((method_name.name, def_id),
+                              MethodIsStaticFlag::from_explicit_self_category(
+                                  explicit_self));
 
                   if is_exported {
                       self.external_exports.insert(method_def_id);
@@ -3678,6 +3705,13 @@ impl<'a> Resolver<'a> {
                                     this.resolve_type(&*argument.ty);
                                 }
 
+                                match ty_m.explicit_self.node {
+                                    SelfExplicit(ref typ, _) => {
+                                        this.resolve_type(*typ)
+                                    }
+                                    _ => {}
+                                }
+
                                 this.resolve_type(&*ty_m.decl.output);
                             });
                           }
@@ -4009,7 +4043,14 @@ impl<'a> Resolver<'a> {
                                                 method.id,
                                                 rib_kind);
 
-        self.resolve_function(rib_kind, Some(method.pe_fn_decl()), type_parameters,
+        match method.pe_explicit_self().node {
+            SelfExplicit(ref typ, _) => self.resolve_type(*typ),
+            _ => {}
+        }
+
+        self.resolve_function(rib_kind,
+                              Some(method.pe_fn_decl()),
+                              type_parameters,
                               method.pe_body());
     }
 
@@ -4765,7 +4806,7 @@ impl<'a> Resolver<'a> {
                 match containing_module.def_id.get() {
                     Some(def_id) => {
                         match self.method_map.borrow().find(&(ident.name, def_id)) {
-                            Some(x) if *x == SelfStatic => (),
+                            Some(&MethodIsStatic) => (),
                             None => (),
                             _ => {
                                 debug!("containing module was a trait or impl \
@@ -5037,7 +5078,7 @@ impl<'a> Resolver<'a> {
                 let path_str = self.path_idents_to_string(&trait_ref.path);
 
                 match method_map.find(&(name, did)) {
-                    Some(&SelfStatic) => return StaticTraitMethod(path_str),
+                    Some(&MethodIsStatic) => return StaticTraitMethod(path_str),
                     Some(_) => return TraitMethod,
                     None => {}
                 }

src/librustc/middle/trans/meth.rs

@@ -502,15 +502,12 @@ fn emit_vtable_methods(bcx: &Block,
                                                        ExprId(0),
                                                        substs.clone(),
                                                        vtables.clone());
-            match m.explicit_self {
-                ast::SelfValue(_) => {
-                    fn_ref = trans_unboxing_shim(bcx,
-                                                 fn_ref,
-                                                 &*m,
-                                                 m_id,
-                                                 substs.clone());
-                },
-                _ => {}
+            if m.explicit_self == ty::ByValueExplicitSelfCategory {
+                fn_ref = trans_unboxing_shim(bcx,
+                                             fn_ref,
+                                             &*m,
+                                             m_id,
+                                             substs.clone());
             }
             fn_ref
         }

src/librustc/middle/ty.rs

@@ -85,7 +85,7 @@ pub struct Method {
     pub ident: ast::Ident,
     pub generics: ty::Generics,
     pub fty: BareFnTy,
-    pub explicit_self: ast::ExplicitSelf_,
+    pub explicit_self: ExplicitSelfCategory,
     pub vis: ast::Visibility,
     pub def_id: ast::DefId,
     pub container: MethodContainer,
@@ -98,7 +98,7 @@ impl Method {
     pub fn new(ident: ast::Ident,
                generics: ty::Generics,
                fty: BareFnTy,
-               explicit_self: ast::ExplicitSelf_,
+               explicit_self: ExplicitSelfCategory,
                vis: ast::Visibility,
                def_id: ast::DefId,
                container: MethodContainer,
@@ -311,6 +311,9 @@ pub struct ctxt {
     /// (inferred) variance.
     pub item_variance_map: RefCell<DefIdMap<Rc<ItemVariances>>>,
 
+    /// True if the variance has been computed yet; false otherwise.
+    pub variance_computed: Cell<bool>,
+
     /// A mapping from the def ID of an enum or struct type to the def ID
     /// of the method that implements its destructor. If the type is not
     /// present in this map, it does not have a destructor. This map is
@@ -1055,6 +1058,7 @@ pub fn mk_ctxt(s: Session,
     ctxt {
         named_region_map: named_region_map,
         item_variance_map: RefCell::new(DefIdMap::new()),
+        variance_computed: Cell::new(false),
         interner: RefCell::new(FnvHashMap::new()),
         next_id: Cell::new(primitives::LAST_PRIMITIVE_ID),
         sess: s,
@@ -4767,3 +4771,13 @@ impl mc::Typer for ty::ctxt {
         self.upvar_borrow_map.borrow().get_copy(&upvar_id)
     }
 }
+
+/// The category of explicit self.
+#[deriving(Clone, Eq, PartialEq)]
+pub enum ExplicitSelfCategory {
+    StaticExplicitSelfCategory,
+    ByValueExplicitSelfCategory,
+    ByReferenceExplicitSelfCategory(Region, ast::Mutability),
+    ByBoxExplicitSelfCategory,
+}
+