Prohibit unconstrained lifetimes that appear in associated types

src/librustc/metadata/tydecode.rs

@@ -341,7 +341,12 @@ fn parse_region_<F>(st: &mut PState, conv: &mut F) -> ty::Region where
         let index = parse_u32(st);
         assert_eq!(next(st), '|');
         let nm = token::str_to_ident(&parse_str(st, ']'));
-        ty::ReEarlyBound(node_id, space, index, nm.name)
+        ty::ReEarlyBound(ty::EarlyBoundRegion {
+            param_id: node_id,
+            space: space,
+            index: index,
+            name: nm.name
+        })
       }
       'f' => {
         assert_eq!(next(st), '[');

src/librustc/metadata/tyencode.rs

@@ -241,12 +241,12 @@ pub fn enc_region(w: &mut Encoder, cx: &ctxt, r: ty::Region) {
             enc_bound_region(w, cx, br);
             mywrite!(w, "]");
         }
-        ty::ReEarlyBound(node_id, space, index, name) => {
+        ty::ReEarlyBound(ref data) => {
             mywrite!(w, "B[{}|{}|{}|{}]",
-                     node_id,
-                     space.to_uint(),
-                     index,
-                     token::get_name(name));
+                     data.param_id,
+                     data.space.to_uint(),
+                     data.index,
+                     token::get_name(data.name));
         }
         ty::ReFree(ref fr) => {
             mywrite!(w, "f[");

src/librustc/middle/astencode.rs

@@ -496,8 +496,13 @@ impl tr for ty::Region {
             ty::ReLateBound(debruijn, br) => {
                 ty::ReLateBound(debruijn, br.tr(dcx))
             }
-            ty::ReEarlyBound(id, space, index, ident) => {
-                ty::ReEarlyBound(dcx.tr_id(id), space, index, ident)
+            ty::ReEarlyBound(data) => {
+                ty::ReEarlyBound(ty::EarlyBoundRegion {
+                    param_id: dcx.tr_id(data.param_id),
+                    space: data.space,
+                    index: data.index,
+                    name: data.name,
+                })
             }
             ty::ReScope(scope) => {
                 ty::ReScope(scope.tr(dcx))

src/librustc/middle/region.rs

@@ -603,14 +603,11 @@ 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, _)) => {
+                (ty::ReEarlyBound(data_a), ty::ReEarlyBound(data_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
+                    // implementations. Yuck.
+                    data_a == data_b
                 }
 
                 _ => {

src/librustc/middle/subst.rs

@@ -622,11 +622,11 @@ impl<'a, 'tcx> TypeFolder<'tcx> for SubstFolder<'a, 'tcx> {
         // regions that appear in a function signature is done using
         // the specialized routine `ty::replace_late_regions()`.
         match r {
-            ty::ReEarlyBound(_, space, i, region_name) => {
+            ty::ReEarlyBound(data) => {
                 match self.substs.regions {
                     ErasedRegions => ty::ReStatic,
                     NonerasedRegions(ref regions) =>
-                        match regions.opt_get(space, i as usize) {
+                        match regions.opt_get(data.space, data.index as usize) {
                             Some(&r) => {
                                 self.shift_region_through_binders(r)
                             }
@@ -635,11 +635,12 @@ impl<'a, 'tcx> TypeFolder<'tcx> for SubstFolder<'a, 'tcx> {
                                 self.tcx().sess.span_bug(
                                     span,
                                     &format!("Type parameter out of range \
-                                     when substituting in region {} (root type={}) \
-                                     (space={:?}, index={})",
-                                    region_name.as_str(),
-                                    self.root_ty.repr(self.tcx()),
-                                    space, i));
+                                              when substituting in region {} (root type={}) \
+                                              (space={:?}, index={})",
+                                             data.name.as_str(),
+                                             self.root_ty.repr(self.tcx()),
+                                             data.space,
+                                             data.index));
                             }
                         }
                 }

src/librustc/middle/ty.rs

@@ -1134,10 +1134,7 @@ pub enum Region {
     // Region bound in a type or fn declaration which will be
     // substituted 'early' -- that is, at the same time when type
     // parameters are substituted.
-    ReEarlyBound(/* param id */ ast::NodeId,
-                 subst::ParamSpace,
-                 /*index*/ u32,
-                 ast::Name),
+    ReEarlyBound(EarlyBoundRegion),
 
     // Region bound in a function scope, which will be substituted when the
     // function is called.
@@ -1169,6 +1166,14 @@ pub enum Region {
     ReEmpty,
 }
 
+#[derive(Copy, Clone, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable, Debug)]
+pub struct EarlyBoundRegion {
+    pub param_id: ast::NodeId,
+    pub space: subst::ParamSpace,
+    pub index: u32,
+    pub name: ast::Name,
+}
+
 /// Upvars do not get their own node-id. Instead, we use the pair of
 /// the original var id (that is, the root variable that is referenced
 /// by the upvar) and the id of the closure expression.
@@ -1761,7 +1766,12 @@ pub struct RegionParameterDef {
 
 impl RegionParameterDef {
     pub fn to_early_bound_region(&self) -> ty::Region {
-        ty::ReEarlyBound(self.def_id.node, self.space, self.index, self.name)
+        ty::ReEarlyBound(ty::EarlyBoundRegion {
+            param_id: self.def_id.node,
+            space: self.space,
+            index: self.index,
+            name: self.name,
+        })
     }
     pub fn to_bound_region(&self) -> ty::BoundRegion {
         ty::BoundRegion::BrNamed(self.def_id, self.name)
@@ -7071,8 +7081,7 @@ pub fn make_substs_for_receiver_types<'tcx>(tcx: &ty::ctxt<'tcx>,
     let meth_regions: Vec<ty::Region> =
         method.generics.regions.get_slice(subst::FnSpace)
               .iter()
-              .map(|def| ty::ReEarlyBound(def.def_id.node, def.space,
-                                          def.index, def.name))
+              .map(|def| def.to_early_bound_region())
               .collect();
     trait_ref.substs.clone().with_method(meth_tps, meth_regions)
 }

src/librustc/util/ppaux.rs

@@ -163,8 +163,8 @@ pub fn explain_region_and_span(cx: &ctxt, region: ty::Region)
 
       ReEmpty => { ("the empty lifetime".to_string(), None) }
 
-      ReEarlyBound(_, _, _, name) => {
-        (format!("{}", token::get_name(name)), None)
+      ReEarlyBound(ref data) => {
+        (format!("{}", token::get_name(data.name)), None)
       }
 
       // I believe these cases should not occur (except when debugging,
@@ -223,8 +223,8 @@ pub fn region_to_string(cx: &ctxt, prefix: &str, space: bool, region: Region) ->
     // `explain_region()` or `note_and_explain_region()`.
     match region {
         ty::ReScope(_) => prefix.to_string(),
-        ty::ReEarlyBound(_, _, _, name) => {
-            token::get_name(name).to_string()
+        ty::ReEarlyBound(ref data) => {
+            token::get_name(data.name).to_string()
         }
         ty::ReLateBound(_, br) => bound_region_to_string(cx, prefix, space, br),
         ty::ReFree(ref fr) => bound_region_to_string(cx, prefix, space, fr.bound_region),
@@ -899,12 +899,12 @@ impl<'tcx> Repr<'tcx> for ty::BoundRegion {
 impl<'tcx> Repr<'tcx> for ty::Region {
     fn repr(&self, tcx: &ctxt) -> String {
         match *self {
-            ty::ReEarlyBound(id, space, index, name) => {
+            ty::ReEarlyBound(ref data) => {
                 format!("ReEarlyBound({}, {:?}, {}, {})",
-                               id,
-                               space,
-                               index,
-                               token::get_name(name))
+                        data.param_id,
+                        data.space,
+                        data.index,
+                        token::get_name(data.name))
             }
 
             ty::ReLateBound(binder_id, ref bound_region) => {

src/librustc_driver/test.rs

@@ -290,7 +290,12 @@ impl<'a, 'tcx> Env<'a, 'tcx> {
                           -> ty::Region
     {
         let name = token::intern(name);
-        ty::ReEarlyBound(ast::DUMMY_NODE_ID, space, index, name)
+        ty::ReEarlyBound(ty::EarlyBoundRegion {
+            param_id: ast::DUMMY_NODE_ID,
+            space: space,
+            index: index,
+            name: name
+        })
     }
 
     pub fn re_late_bound_with_debruijn(&self, id: u32, debruijn: ty::DebruijnIndex) -> ty::Region {

src/librustc_typeck/astconv.rs

@@ -161,7 +161,12 @@ pub fn ast_region_to_region(tcx: &ty::ctxt, lifetime: &ast::Lifetime)
         }
 
         Some(&rl::DefEarlyBoundRegion(space, index, id)) => {
-            ty::ReEarlyBound(id, space, index, lifetime.name)
+            ty::ReEarlyBound(ty::EarlyBoundRegion {
+                param_id: id,
+                space: space,
+                index: index,
+                name: lifetime.name
+            })
         }
 
         Some(&rl::DefFreeRegion(scope, id)) => {

src/librustc_typeck/check/wf.rs

@@ -10,7 +10,7 @@
 
 use astconv::AstConv;
 use check::{FnCtxt, Inherited, blank_fn_ctxt, vtable, regionck};
-use constrained_type_params::identify_constrained_type_params;
+use constrained_type_params::{identify_constrained_type_params, Parameter};
 use CrateCtxt;
 use middle::region;
 use middle::subst::{self, TypeSpace, FnSpace, ParamSpace, SelfSpace};
@@ -287,10 +287,11 @@ impl<'ccx, 'tcx> CheckTypeWellFormedVisitor<'ccx, 'tcx> {
 
         let mut constrained_parameters: HashSet<_> =
             variances.types
-            .iter_enumerated()
-            .filter(|&(_, _, &variance)| variance != ty::Bivariant)
-            .map(|(space, index, _)| self.param_ty(ast_generics, space, index))
-            .collect();
+                     .iter_enumerated()
+                     .filter(|&(_, _, &variance)| variance != ty::Bivariant)
+                     .map(|(space, index, _)| self.param_ty(ast_generics, space, index))
+                     .map(|p| Parameter::Type(p))
+                     .collect();
 
         identify_constrained_type_params(self.tcx(),
                                          ty_predicates.predicates.as_slice(),
@@ -299,7 +300,7 @@ impl<'ccx, 'tcx> CheckTypeWellFormedVisitor<'ccx, 'tcx> {
 
         for (space, index, _) in variances.types.iter_enumerated() {
             let param_ty = self.param_ty(ast_generics, space, index);
-            if constrained_parameters.contains(&param_ty) {
+            if constrained_parameters.contains(&Parameter::Type(param_ty)) {
                 continue;
             }
             let span = self.ty_param_span(ast_generics, item, space, index);