Switch to using predicates to drive checking. Correct various tests --

in most cases, just the error message changed, but in some cases we
are reporting new errors that OUGHT to have been reported before but
we're overlooked (mostly involving the `'static` bound on `Send`).

Author: nikomatsakis

src/libcore/kinds.rs

@@ -19,7 +19,7 @@
 
 /// Types able to be transferred across task boundaries.
 #[lang="send"]
-pub trait Send for Sized? {
+pub trait Send for Sized? : 'static {
     // empty.
 }
 

src/librustc/metadata/common.rs

@@ -251,3 +251,7 @@ pub const tag_type_param_def: uint = 0xa5;
 
 pub const tag_item_generics: uint = 0xa6;
 pub const tag_method_ty_generics: uint = 0xa7;
+
+pub const tag_predicate: uint = 0xa8;
+pub const tag_predicate_space: uint = 0xa9;
+pub const tag_predicate_data: uint = 0xb0;

src/librustc/metadata/decoder.rs

@@ -23,7 +23,8 @@ use metadata::csearch;
 use metadata::cstore;
 use metadata::tydecode::{parse_ty_data, parse_region_data, parse_def_id,
                          parse_type_param_def_data, parse_bounds_data,
-                         parse_bare_fn_ty_data, parse_trait_ref_data};
+                         parse_bare_fn_ty_data, parse_trait_ref_data,
+                         parse_predicate_data};
 use middle::def;
 use middle::lang_items;
 use middle::resolve::{TraitItemKind, TypeTraitItemKind};
@@ -1437,7 +1438,18 @@ fn doc_generics<'tcx>(base_doc: rbml::Doc,
         true
     });
 
-    let predicates = subst::VecPerParamSpace::empty(); // TODO fix in later commit
+    let mut predicates = subst::VecPerParamSpace::empty();
+    reader::tagged_docs(doc, tag_predicate, |predicate_doc| {
+        let space_doc = reader::get_doc(predicate_doc, tag_predicate_space);
+        let space = subst::ParamSpace::from_uint(reader::doc_as_u8(space_doc) as uint);
+
+        let data_doc = reader::get_doc(predicate_doc, tag_predicate_data);
+        let data = parse_predicate_data(data_doc.data, data_doc.start, cdata.cnum, tcx,
+                                        |_, did| translate_def_id(cdata, did));
+
+        predicates.push(space, data);
+        true
+    });
 
     ty::Generics { types: types, regions: regions, predicates: predicates }
 }

src/librustc/metadata/encoder.rs

@@ -803,6 +803,18 @@ fn encode_generics<'a, 'tcx>(rbml_w: &mut Encoder,
         rbml_w.end_tag();
     }
 
+    for (space, _, predicate) in generics.predicates.iter_enumerated() {
+        rbml_w.start_tag(tag_predicate);
+
+        rbml_w.wr_tagged_u8(tag_predicate_space, space as u8);
+
+        rbml_w.start_tag(tag_predicate_data);
+        tyencode::enc_predicate(rbml_w.writer, ty_str_ctxt, predicate);
+        rbml_w.end_tag();
+
+        rbml_w.end_tag();
+    }
+
     rbml_w.end_tag();
 }
 

src/librustc/metadata/tydecode.rs

@@ -470,7 +470,7 @@ fn parse_ty<'a, 'tcx>(st: &mut PState<'a, 'tcx>, conv: conv_did) -> Ty<'tcx> {
         st.tcx.rcache.borrow_mut().insert(key, tt);
         return tt;
       }
-      '"' => {
+      '\"' => {
         let _ = parse_def(st, TypeWithId, |x,y| conv(x,y));
         let inner = parse_ty(st, |x,y| conv(x,y));
         inner
@@ -646,6 +646,33 @@ pub fn parse_def_id(buf: &[u8]) -> ast::DefId {
     ast::DefId { krate: crate_num, node: def_num }
 }
 
+pub fn parse_predicate_data<'tcx>(data: &[u8],
+                                  start: uint,
+                                  crate_num: ast::CrateNum,
+                                  tcx: &ty::ctxt<'tcx>,
+                                  conv: conv_did)
+                                  -> ty::Predicate<'tcx>
+{
+    let mut st = parse_state_from_data(data, crate_num, start, tcx);
+    parse_predicate(&mut st, conv)
+}
+
+pub fn parse_predicate<'a,'tcx>(st: &mut PState<'a, 'tcx>,
+                                conv: conv_did)
+                                -> ty::Predicate<'tcx>
+{
+    match next(st) {
+        't' => ty::Predicate::Trait(Rc::new(parse_trait_ref(st, conv))),
+        'e' => ty::Predicate::Equate(parse_ty(st, |x,y| conv(x,y)),
+                                     parse_ty(st, |x,y| conv(x,y))),
+        'r' => ty::Predicate::RegionOutlives(parse_region(st, |x,y| conv(x,y)),
+                                             parse_region(st, |x,y| conv(x,y))),
+        'o' => ty::Predicate::TypeOutlives(parse_ty(st, |x,y| conv(x,y)),
+                                           parse_region(st, |x,y| conv(x,y))),
+        c => panic!("Encountered invalid character in metadata: {}", c)
+    }
+}
+
 pub fn parse_type_param_def_data<'tcx>(data: &[u8], start: uint,
                                        crate_num: ast::CrateNum, tcx: &ty::ctxt<'tcx>,
                                        conv: conv_did) -> ty::TypeParameterDef<'tcx>

src/librustc/metadata/tyencode.rs

@@ -413,3 +413,30 @@ pub fn enc_type_param_def<'a, 'tcx>(w: &mut SeekableMemWriter, cx: &ctxt<'a, 'tc
     enc_bounds(w, cx, &v.bounds);
     enc_opt(w, v.default, |w, t| enc_ty(w, cx, t));
 }
+
+pub fn enc_predicate<'a, 'tcx>(w: &mut SeekableMemWriter,
+                               cx: &ctxt<'a, 'tcx>,
+                               p: &ty::Predicate<'tcx>)
+{
+    match *p {
+        ty::Predicate::Trait(ref trait_ref) => {
+            mywrite!(w, "t");
+            enc_trait_ref(w, cx, &**trait_ref);
+        }
+        ty::Predicate::Equate(a, b) => {
+            mywrite!(w, "e");
+            enc_ty(w, cx, a);
+            enc_ty(w, cx, b);
+        }
+        ty::Predicate::RegionOutlives(a, b) => {
+            mywrite!(w, "r");
+            enc_region(w, cx, a);
+            enc_region(w, cx, b);
+        }
+        ty::Predicate::TypeOutlives(a, b) => {
+            mywrite!(w, "o");
+            enc_ty(w, cx, a);
+            enc_region(w, cx, b);
+        }
+    }
+}

src/librustc/middle/check_static.rs

@@ -31,6 +31,7 @@ use middle::infer;
 use middle::traits;
 use middle::mem_categorization as mc;
 use middle::expr_use_visitor as euv;
+use util::common::ErrorReported;
 use util::nodemap::NodeSet;
 
 use syntax::ast;
@@ -119,15 +120,17 @@ impl<'a, 'tcx> CheckStaticVisitor<'a, 'tcx> {
         let ty = ty::node_id_to_type(self.tcx, e.id);
         let infcx = infer::new_infer_ctxt(self.tcx);
         let mut fulfill_cx = traits::FulfillmentContext::new();
-        let cause = traits::ObligationCause::dummy();
-        let obligation = traits::obligation_for_builtin_bound(self.tcx, cause, ty,
-                                                              ty::BoundSync);
-        fulfill_cx.register_obligation(self.tcx, obligation.unwrap());
-        let env = ty::empty_parameter_environment();
-        let result = fulfill_cx.select_all_or_error(&infcx, &env, self.tcx).is_ok();
-        if !result {
-            self.tcx.sess.span_err(e.span, "shared static items must have a \
-                                            type which implements Sync");
+        match traits::trait_ref_for_builtin_bound(self.tcx, ty::BoundSync, ty) {
+            Ok(trait_ref) => {
+                fulfill_cx.register_trait_ref(self.tcx, trait_ref,
+                                              traits::ObligationCause::dummy());
+                let env = ty::empty_parameter_environment();
+                if !fulfill_cx.select_all_or_error(&infcx, &env, self.tcx).is_ok() {
+                    self.tcx.sess.span_err(e.span, "shared static items must have a \
+                                                    type which implements Sync");
+                }
+            }
+            Err(ErrorReported) => { }
         }
     }
 }