librustc: Implement `&static` as the replacement for `Durable`. r=nmatsakis

7 files changed, 45 insertions, 23 deletions

diff --git a/src/libsyntax/ast.rs b/src/libsyntax/ast.rs
index 072a7e94fe9..2cd873414c4 100644
--- a/src/libsyntax/ast.rs
+++ b/src/libsyntax/ast.rs
@@ -110,7 +110,10 @@ const crate_node_id: node_id = 0;
 // typeck::collect::compute_bounds matches these against
 // the "special" built-in traits (see middle::lang_items) and
 // detects Copy, Send, Owned, and Const.
-enum ty_param_bound = @Ty;
+enum ty_param_bound {
+    TraitTyParamBound(@Ty),
+    RegionTyParamBound
+}
 
 #[auto_encode]
 #[auto_decode]
diff --git a/src/libsyntax/ext/auto_encode.rs b/src/libsyntax/ext/auto_encode.rs
index 90df6fde8e3..2b3fefd6e51 100644
--- a/src/libsyntax/ext/auto_encode.rs
+++ b/src/libsyntax/ext/auto_encode.rs
@@ -245,7 +245,7 @@ priv impl ext_ctxt {
         path: @ast::path,
         bounds: @~[ast::ty_param_bound]
     ) -> ast::ty_param {
-        let bound = ast::ty_param_bound(@{
+        let bound = ast::TraitTyParamBound(@{
             id: self.next_id(),
             node: ast::ty_path(path, self.next_id()),
             span: span,
@@ -397,7 +397,7 @@ fn mk_impl(
     let mut trait_tps = vec::append(
         ~[ty_param],
          do tps.map |tp| {
-            let t_bound = ast::ty_param_bound(@{
+            let t_bound = ast::TraitTyParamBound(@{
                 id: cx.next_id(),
                 node: ast::ty_path(path, cx.next_id()),
                 span: span,
diff --git a/src/libsyntax/ext/deriving.rs b/src/libsyntax/ext/deriving.rs
index 8e36dc01e2a..afce1edf158 100644
--- a/src/libsyntax/ext/deriving.rs
+++ b/src/libsyntax/ext/deriving.rs
@@ -13,13 +13,13 @@
 
 use core::prelude::*;
 
-use ast::{Ty, and, bind_by_ref, binop, deref, enum_def, enum_variant_kind};
-use ast::{expr, expr_match, ident, item, item_, item_struct, item_enum};
-use ast::{item_impl, m_imm, meta_item, method, named_field, or, pat};
-use ast::{pat_ident, pat_wild, public, pure_fn, re_anon, spanned, stmt};
-use ast::{struct_def, struct_variant_kind, sty_by_ref, sty_region};
-use ast::{tuple_variant_kind, ty_nil, ty_param, ty_param_bound, ty_path};
-use ast::{ty_rptr, unnamed_field, variant};
+use ast::{TraitTyParamBound, Ty, and, bind_by_ref, binop, deref, enum_def};
+use ast::{enum_variant_kind, expr, expr_match, ident, item, item_};
+use ast::{item_enum, item_impl, item_struct, m_imm, meta_item, method};
+use ast::{named_field, or, pat, pat_ident, pat_wild, public, pure_fn};
+use ast::{re_anon, spanned, stmt, struct_def, struct_variant_kind};
+use ast::{sty_by_ref, sty_region, tuple_variant_kind, ty_nil, ty_param};
+use ast::{ty_param_bound, ty_path, ty_rptr, unnamed_field, variant};
 use ext::base::ext_ctxt;
 use ext::build;
 use codemap::span;
@@ -211,7 +211,7 @@ fn create_derived_impl(cx: ext_ctxt,
         let bound = build::mk_ty_path_global(cx,
                                              span,
                                              trait_path.map(|x| *x));
-        let bounds = @~[ ty_param_bound(bound) ];
+        let bounds = @~[ TraitTyParamBound(bound) ];
         let impl_ty_param = build::mk_ty_param(cx, ty_param.ident, bounds);
         impl_ty_params.push(move impl_ty_param);
     }
diff --git a/src/libsyntax/fold.rs b/src/libsyntax/fold.rs
index 272ad3456e5..bca2336bc8c 100644
--- a/src/libsyntax/fold.rs
+++ b/src/libsyntax/fold.rs
@@ -141,7 +141,10 @@ fn fold_fn_decl(decl: ast::fn_decl, fld: ast_fold) -> ast::fn_decl {
 }
 
 fn fold_ty_param_bound(tpb: ty_param_bound, fld: ast_fold) -> ty_param_bound {
-    ty_param_bound(fld.fold_ty(*tpb))
+    match tpb {
+        TraitTyParamBound(ty) => TraitTyParamBound(fld.fold_ty(ty)),
+        RegionTyParamBound => RegionTyParamBound
+    }
 }
 
 fn fold_ty_param(tp: ty_param, fld: ast_fold) -> ty_param {
diff --git a/src/libsyntax/parse/parser.rs b/src/libsyntax/parse/parser.rs
index 1a549fc93d5..6974ac508aa 100644
--- a/src/libsyntax/parse/parser.rs
+++ b/src/libsyntax/parse/parser.rs
@@ -10,7 +10,8 @@
 
 use core::prelude::*;
 
-use ast::{ProtoBox, ProtoUniq, provided, public, pure_fn, purity, re_static};
+use ast::{ProtoBox, ProtoUniq, RegionTyParamBound, TraitTyParamBound};
+use ast::{provided, public, pure_fn, purity, re_static};
 use ast::{_mod, add, arg, arm, attribute, bind_by_ref, bind_infer};
 use ast::{bind_by_value, bind_by_move, bitand, bitor, bitxor, blk};
 use ast::{blk_check_mode, box, by_copy, by_move, by_ref, by_val};
@@ -2401,8 +2402,16 @@ impl Parser {
     fn parse_optional_ty_param_bounds() -> @~[ty_param_bound] {
         let mut bounds = ~[];
         if self.eat(token::COLON) {
-            while is_ident(self.token) {
-                if is_ident(self.token) {
+            loop {
+                if self.eat(token::BINOP(token::AND)) {
+                    if self.eat_keyword(~"static") {
+                        bounds.push(RegionTyParamBound);
+                    } else {
+                        self.span_err(copy self.span,
+                                      ~"`&static` is the only permissible \
+                                        region bound here");
+                    }
+                } else if is_ident(self.token) {
                     let maybe_bound = match self.token {
                       token::IDENT(copy sid, _) => {
                         match *self.id_to_str(sid) {
@@ -2415,7 +2424,7 @@ impl Parser {
                                           ObsoleteLowerCaseKindBounds);
                             // Bogus value, but doesn't matter, since
                             // is an error
-                            Some(ty_param_bound(self.mk_ty_path(sid)))
+                            Some(TraitTyParamBound(self.mk_ty_path(sid)))
                           }
 
                           _ => None
@@ -2430,11 +2439,12 @@ impl Parser {
                             bounds.push(bound);
                         }
                         None => {
-                            bounds.push(ty_param_bound(self.parse_ty(false)));
+                            let ty = self.parse_ty(false);
+                            bounds.push(TraitTyParamBound(ty));
                         }
                     }
                 } else {
-                    bounds.push(ty_param_bound(self.parse_ty(false)));
+                    break;
                 }
             }
         }
diff --git a/src/libsyntax/print/pprust.rs b/src/libsyntax/print/pprust.rs
index 272c35152bb..f7117cc7043 100644
--- a/src/libsyntax/print/pprust.rs
+++ b/src/libsyntax/print/pprust.rs
@@ -10,7 +10,7 @@
 
 use core::prelude::*;
 
-use ast::{required, provided};
+use ast::{RegionTyParamBound, TraitTyParamBound, required, provided};
 use ast;
 use ast_util;
 use ast_util::{operator_prec};
@@ -1791,9 +1791,12 @@ fn print_arg_mode(s: ps, m: ast::mode) {
 fn print_bounds(s: ps, bounds: @~[ast::ty_param_bound]) {
     if bounds.is_not_empty() {
         word(s.s, ~":");
-        for vec::each(*bounds) |bound| {
+        for vec::each(*bounds) |&bound| {
             nbsp(s);
-            print_type(s, **bound);
+            match bound {
+                TraitTyParamBound(ty) => print_type(s, ty),
+                RegionTyParamBound => word(s.s, ~"&static"),
+            }
         }
     }
 }
diff --git a/src/libsyntax/visit.rs b/src/libsyntax/visit.rs
index 0da6396253e..25ea76d9b51 100644
--- a/src/libsyntax/visit.rs
+++ b/src/libsyntax/visit.rs
@@ -288,8 +288,11 @@ fn visit_foreign_item<E>(ni: @foreign_item, e: E, v: vt<E>) {
 }
 
 fn visit_ty_param_bounds<E>(bounds: @~[ty_param_bound], e: E, v: vt<E>) {
-    for vec::each(*bounds) |bound| {
-        (v.visit_ty)(**bound, e, v)
+    for bounds.each |&bound| {
+        match bound {
+            TraitTyParamBound(ty) => (v.visit_ty)(ty, e, v),
+            RegionTyParamBound => ()
+        }
     }
 }