auto merge of #7291 : alexcrichton/rust/static-mut, r=huonw

This adds both `static mut` items and `static mut` foreign items. This involved changing far less code than I thought it was going to, but the tests seem to pass and the variables seem functional.

I'm more than willing to write more tests, so suggestions are welcome!

Closes #553

7 files changed, 24 insertions, 16 deletions

diff --git a/src/libsyntax/ast.rs b/src/libsyntax/ast.rs
index 2e3d557daa9..c7f3b41475f 100644
--- a/src/libsyntax/ast.rs
+++ b/src/libsyntax/ast.rs
@@ -190,7 +190,7 @@ pub enum def {
     def_self_ty(/* trait id */ node_id),
     def_mod(def_id),
     def_foreign_mod(def_id),
-    def_const(def_id),
+    def_static(def_id, bool /* is_mutbl */),
     def_arg(node_id, bool /* is_mutbl */),
     def_local(node_id, bool /* is_mutbl */),
     def_variant(def_id /* enum */, def_id /* variant */),
@@ -1095,7 +1095,7 @@ pub struct item {
 
 #[deriving(Eq, Encodable, Decodable)]
 pub enum item_ {
-    item_const(@Ty, @expr),
+    item_static(@Ty, mutability, @expr),
     item_fn(fn_decl, purity, AbiSet, Generics, blk),
     item_mod(_mod),
     item_foreign_mod(foreign_mod),
@@ -1124,7 +1124,7 @@ pub struct foreign_item {
 #[deriving(Eq, Encodable, Decodable)]
 pub enum foreign_item_ {
     foreign_item_fn(fn_decl, purity, Generics),
-    foreign_item_const(@Ty)
+    foreign_item_static(@Ty, /* is_mutbl */ bool),
 }
 
 // The data we save and restore about an inlined item or method.  This is not
diff --git a/src/libsyntax/ast_map.rs b/src/libsyntax/ast_map.rs
index a0e1ec69350..421c4c566b5 100644
--- a/src/libsyntax/ast_map.rs
+++ b/src/libsyntax/ast_map.rs
@@ -339,7 +339,7 @@ pub fn node_id_to_str(map: map, id: node_id, itr: @ident_interner) -> ~str {
       Some(&node_item(item, path)) => {
         let path_str = path_ident_to_str(path, item.ident, itr);
         let item_str = match item.node {
-          item_const(*) => ~"const",
+          item_static(*) => ~"static",
           item_fn(*) => ~"fn",
           item_mod(*) => ~"mod",
           item_foreign_mod(*) => ~"foreign mod",
diff --git a/src/libsyntax/ast_util.rs b/src/libsyntax/ast_util.rs
index 24cf5662a36..227d700452b 100644
--- a/src/libsyntax/ast_util.rs
+++ b/src/libsyntax/ast_util.rs
@@ -59,7 +59,7 @@ pub fn variant_def_ids(d: def) -> Option<(def_id, def_id)> {
 pub fn def_id_of_def(d: def) -> def_id {
     match d {
       def_fn(id, _) | def_static_method(id, _, _) | def_mod(id) |
-      def_foreign_mod(id) | def_const(id) |
+      def_foreign_mod(id) | def_static(id, _) |
       def_variant(_, id) | def_ty(id) | def_ty_param(id, _) |
       def_use(id) | def_struct(id) | def_trait(id) => {
         id
diff --git a/src/libsyntax/fold.rs b/src/libsyntax/fold.rs
index 4bd2c0a3de1..25839fb4633 100644
--- a/src/libsyntax/fold.rs
+++ b/src/libsyntax/fold.rs
@@ -236,8 +236,8 @@ fn noop_fold_foreign_item(ni: @foreign_item, fld: @ast_fold)
                         purity,
                         fold_generics(generics, fld))
                 }
-                foreign_item_const(t) => {
-                    foreign_item_const(fld.fold_ty(t))
+                foreign_item_static(t, m) => {
+                    foreign_item_static(fld.fold_ty(t), m)
                 }
             },
         id: fld.new_id(ni.id),
@@ -270,7 +270,7 @@ fn noop_fold_struct_field(sf: @struct_field, fld: @ast_fold)
 
 pub fn noop_fold_item_underscore(i: &item_, fld: @ast_fold) -> item_ {
     match *i {
-        item_const(t, e) => item_const(fld.fold_ty(t), fld.fold_expr(e)),
+        item_static(t, m, e) => item_static(fld.fold_ty(t), m, fld.fold_expr(e)),
         item_fn(ref decl, purity, abi, ref generics, ref body) => {
             item_fn(
                 fold_fn_decl(decl, fld),
diff --git a/src/libsyntax/parse/parser.rs b/src/libsyntax/parse/parser.rs
index c9ef1a7a33c..d8aab1f68ee 100644
--- a/src/libsyntax/parse/parser.rs
+++ b/src/libsyntax/parse/parser.rs
@@ -33,8 +33,8 @@ use ast::{expr_vec, expr_vstore, expr_vstore_mut_box};
 use ast::{expr_vstore_slice, expr_vstore_box};
 use ast::{expr_vstore_mut_slice, expr_while, extern_fn, field, fn_decl};
 use ast::{expr_vstore_uniq, Onceness, Once, Many};
-use ast::{foreign_item, foreign_item_const, foreign_item_fn, foreign_mod};
-use ast::{ident, impure_fn, inherited, item, item_, item_const};
+use ast::{foreign_item, foreign_item_static, foreign_item_fn, foreign_mod};
+use ast::{ident, impure_fn, inherited, item, item_, item_static};
 use ast::{item_enum, item_fn, item_foreign_mod, item_impl};
 use ast::{item_mac, item_mod, item_struct, item_trait, item_ty, lit, lit_};
 use ast::{lit_bool, lit_float, lit_float_unsuffixed, lit_int};
@@ -3556,13 +3556,14 @@ impl Parser {
     }
 
     fn parse_item_const(&self) -> item_info {
+        let m = if self.eat_keyword(keywords::Mut) {m_mutbl} else {m_imm};
         let id = self.parse_ident();
         self.expect(&token::COLON);
         let ty = self.parse_ty(false);
         self.expect(&token::EQ);
         let e = self.parse_expr();
         self.expect(&token::SEMI);
-        (id, item_const(ty, e), None)
+        (id, item_static(ty, m, e), None)
     }
 
     // parse a mod { ...}  item
@@ -3683,6 +3684,7 @@ impl Parser {
         } else {
             self.expect_keyword(keywords::Static);
         }
+        let mutbl = self.eat_keyword(keywords::Mut);
 
         let ident = self.parse_ident();
         self.expect(&token::COLON);
@@ -3691,7 +3693,7 @@ impl Parser {
         self.expect(&token::SEMI);
         @ast::foreign_item { ident: ident,
                              attrs: attrs,
-                             node: foreign_item_const(ty),
+                             node: foreign_item_static(ty, mutbl),
                              id: self.get_id(),
                              span: mk_sp(lo, hi),
                              vis: vis }
diff --git a/src/libsyntax/print/pprust.rs b/src/libsyntax/print/pprust.rs
index fa22b7ceb71..1a3155337a5 100644
--- a/src/libsyntax/print/pprust.rs
+++ b/src/libsyntax/print/pprust.rs
@@ -458,8 +458,11 @@ pub fn print_foreign_item(s: @ps, item: @ast::foreign_item) {
         word(s.s, ";");
         end(s); // end the outer fn box
       }
-      ast::foreign_item_const(t) => {
+      ast::foreign_item_static(t, m) => {
         head(s, "static");
+        if m {
+            word_space(s, "mut");
+        }
         print_ident(s, item.ident);
         word_space(s, ":");
         print_type(s, t);
@@ -477,8 +480,11 @@ pub fn print_item(s: @ps, item: @ast::item) {
     let ann_node = node_item(s, item);
     (s.ann.pre)(ann_node);
     match item.node {
-      ast::item_const(ty, expr) => {
+      ast::item_static(ty, m, expr) => {
         head(s, visibility_qualified(item.vis, "static"));
+        if m == ast::m_mutbl {
+            word_space(s, "mut");
+        }
         print_ident(s, item.ident);
         word_space(s, ":");
         print_type(s, ty);
diff --git a/src/libsyntax/visit.rs b/src/libsyntax/visit.rs
index 5aa38c0348c..d7914832835 100644
--- a/src/libsyntax/visit.rs
+++ b/src/libsyntax/visit.rs
@@ -148,7 +148,7 @@ fn visit_trait_ref<E: Copy>(tref: @ast::trait_ref, (e, v): (E, vt<E>)) {
 
 pub fn visit_item<E: Copy>(i: @item, (e, v): (E, vt<E>)) {
     match i.node {
-        item_const(t, ex) => {
+        item_static(t, _, ex) => {
             (v.visit_ty)(t, (copy e, v));
             (v.visit_expr)(ex, (copy e, v));
         }
@@ -326,7 +326,7 @@ pub fn visit_foreign_item<E: Copy>(ni: @foreign_item, (e, v): (E, vt<E>)) {
             visit_fn_decl(fd, (copy e, v));
             (v.visit_generics)(generics, (e, v));
         }
-        foreign_item_const(t) => {
+        foreign_item_static(t, _) => {
             (v.visit_ty)(t, (e, v));
         }
     }