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

src/librustc/metadata/decoder.rs

@@ -96,7 +96,8 @@ fn lookup_item(item_id: int, data: @~[u8]) -> ebml::Doc {
 
 #[deriving(Eq)]
 enum Family {
-    Const,                 // c
+    ImmStatic,             // c
+    MutStatic,             // b
     Fn,                    // f
     UnsafeFn,              // u
     PureFn,                // p
@@ -121,7 +122,8 @@ enum Family {
 fn item_family(item: ebml::Doc) -> Family {
     let fam = reader::get_doc(item, tag_items_data_item_family);
     match reader::doc_as_u8(fam) as char {
-      'c' => Const,
+      'c' => ImmStatic,
+      'b' => MutStatic,
       'f' => Fn,
       'u' => UnsafeFn,
       'p' => PureFn,
@@ -320,7 +322,8 @@ fn item_to_def_like(item: ebml::Doc, did: ast::def_id, cnum: ast::crate_num)
     -> def_like {
     let fam = item_family(item);
     match fam {
-        Const     => dl_def(ast::def_const(did)),
+        ImmStatic => dl_def(ast::def_static(did, false)),
+        MutStatic => dl_def(ast::def_static(did, true)),
         Struct    => dl_def(ast::def_struct(did)),
         UnsafeFn  => dl_def(ast::def_fn(did, ast::unsafe_fn)),
         Fn        => dl_def(ast::def_fn(did, ast::impure_fn)),
@@ -899,8 +902,8 @@ pub fn get_item_visibility(cdata: cmd, id: ast::node_id)
 
 fn family_has_type_params(fam: Family) -> bool {
     match fam {
-      Const | ForeignType | Mod | ForeignMod | PublicField | PrivateField
-      | ForeignFn => false,
+      ImmStatic | ForeignType | Mod | ForeignMod | PublicField | PrivateField
+      | ForeignFn | MutStatic => false,
       _           => true
     }
 }
@@ -930,7 +933,8 @@ fn describe_def(items: ebml::Doc, id: ast::def_id) -> ~str {
 
 fn item_family_to_str(fam: Family) -> ~str {
     match fam {
-      Const => ~"const",
+      ImmStatic => ~"static",
+      MutStatic => ~"static mut",
       Fn => ~"fn",
       UnsafeFn => ~"unsafe fn",
       PureFn => ~"pure fn",

src/librustc/metadata/encoder.rs

@@ -785,7 +785,7 @@ fn encode_info_for_item(ecx: &EncodeContext,
     let must_write =
         match item.node {
           item_enum(_, _) | item_impl(*) | item_trait(*) | item_struct(*) |
-          item_mod(*) | item_foreign_mod(*) | item_const(*) => true,
+          item_mod(*) | item_foreign_mod(*) | item_static(*) => true,
           _ => false
         };
     if !must_write && !reachable(ecx, item.id) { return; }
@@ -800,11 +800,15 @@ fn encode_info_for_item(ecx: &EncodeContext,
            ecx.tcx.sess.codemap.span_to_str(item.span));
 
     match item.node {
-      item_const(_, _) => {
+      item_static(_, m, _) => {
         add_to_index();
         ebml_w.start_tag(tag_items_data_item);
         encode_def_id(ebml_w, local_def(item.id));
-        encode_family(ebml_w, 'c');
+        if m == ast::m_mutbl {
+            encode_family(ebml_w, 'b');
+        } else {
+            encode_family(ebml_w, 'c');
+        }
         encode_type(ecx, ebml_w, node_id_to_type(tcx, item.id));
         encode_symbol(ecx, ebml_w, item.id);
         encode_path(ecx, ebml_w, path, ast_map::path_name(item.ident));
@@ -1107,9 +1111,13 @@ fn encode_info_for_foreign_item(ecx: &EncodeContext,
         }
         encode_path(ecx, ebml_w, path, ast_map::path_name(nitem.ident));
       }
-      foreign_item_const(*) => {
+      foreign_item_static(_, mutbl) => {
         encode_def_id(ebml_w, local_def(nitem.id));
-        encode_family(ebml_w, 'c');
+        if mutbl {
+            encode_family(ebml_w, 'b');
+        } else {
+            encode_family(ebml_w, 'c');
+        }
         encode_type(ecx, ebml_w, node_id_to_type(ecx.tcx, nitem.id));
         encode_symbol(ecx, ebml_w, nitem.id);
         encode_path(ecx, ebml_w, path, ast_map::path_name(nitem.ident));

src/librustc/middle/astencode.rs

@@ -384,7 +384,7 @@ impl tr for ast::def {
           ast::def_self(nid, i) => { ast::def_self(xcx.tr_id(nid), i) }
           ast::def_mod(did) => { ast::def_mod(did.tr(xcx)) }
           ast::def_foreign_mod(did) => { ast::def_foreign_mod(did.tr(xcx)) }
-          ast::def_const(did) => { ast::def_const(did.tr(xcx)) }
+          ast::def_static(did, m) => { ast::def_static(did.tr(xcx), m) }
           ast::def_arg(nid, b) => { ast::def_arg(xcx.tr_id(nid), b) }
           ast::def_local(nid, b) => { ast::def_local(xcx.tr_id(nid), b) }
           ast::def_variant(e_did, v_did) => {

src/librustc/middle/check_const.rs

@@ -43,7 +43,7 @@ pub fn check_item(sess: Session,
                   (_is_const, v): (bool,
                                    visit::vt<bool>)) {
     match it.node {
-      item_const(_, ex) => {
+      item_static(_, _, ex) => {
         (v.visit_expr)(ex, (true, v));
         check_item_recursion(sess, ast_map, def_map, it);
       }
@@ -124,7 +124,7 @@ pub fn check_expr(sess: Session,
                              items without type parameters");
             }
             match def_map.find(&e.id) {
-              Some(&def_const(_)) |
+              Some(&def_static(*)) |
               Some(&def_fn(_, _)) |
               Some(&def_variant(_, _)) |
               Some(&def_struct(_)) => { }
@@ -237,7 +237,7 @@ pub fn check_item_recursion(sess: Session,
         match e.node {
           expr_path(*) => {
             match env.def_map.find(&e.id) {
-              Some(&def_const(def_id)) => {
+              Some(&def_static(def_id, _)) => {
                 if ast_util::is_local(def_id) {
                   match env.ast_map.get_copy(&def_id.node) {
                     ast_map::node_item(it, _) => {

src/librustc/middle/check_match.rs

@@ -304,7 +304,7 @@ pub fn pat_ctor_id(cx: @MatchCheckCtxt, p: @pat) -> Option<ctor> {
       pat_ident(_, _, _) | pat_enum(_, _) => {
         match cx.tcx.def_map.find(&pat.id) {
           Some(&def_variant(_, id)) => Some(variant(id)),
-          Some(&def_const(did)) => {
+          Some(&def_static(did, false)) => {
             let const_expr = lookup_const_by_id(cx.tcx, did).get();
             Some(val(eval_const_expr(cx.tcx, const_expr)))
           }
@@ -339,7 +339,7 @@ pub fn is_wild(cx: @MatchCheckCtxt, p: @pat) -> bool {
       pat_wild => { true }
       pat_ident(_, _, _) => {
         match cx.tcx.def_map.find(&pat.id) {
-          Some(&def_variant(_, _)) | Some(&def_const(*)) => { false }
+          Some(&def_variant(_, _)) | Some(&def_static(*)) => { false }
           _ => { true }
         }
       }
@@ -499,7 +499,7 @@ pub fn specialize(cx: @MatchCheckCtxt,
                             None
                         }
                     }
-                    Some(&def_const(did)) => {
+                    Some(&def_static(did, _)) => {
                         let const_expr =
                             lookup_const_by_id(cx.tcx, did).get();
                         let e_v = eval_const_expr(cx.tcx, const_expr);
@@ -549,7 +549,7 @@ pub fn specialize(cx: @MatchCheckCtxt,
             }
             pat_enum(_, args) => {
                 match cx.tcx.def_map.get_copy(&pat_id) {
-                    def_const(did) => {
+                    def_static(did, _) => {
                         let const_expr =
                             lookup_const_by_id(cx.tcx, did).get();
                         let e_v = eval_const_expr(cx.tcx, const_expr);
@@ -790,7 +790,7 @@ pub fn is_refutable(cx: @MatchCheckCtxt, pat: &pat) -> bool {
             return true;
         }
       }
-      Some(&def_const(*)) => return true,
+      Some(&def_static(*)) => return true,
       _ => ()
     }
 

src/librustc/middle/const_eval.rs

@@ -166,7 +166,7 @@ pub fn classify(e: @expr,
 
 pub fn lookup_const(tcx: ty::ctxt, e: @expr) -> Option<@expr> {
     match tcx.def_map.find(&e.id) {
-        Some(&ast::def_const(def_id)) => lookup_const_by_id(tcx, def_id),
+        Some(&ast::def_static(def_id, false)) => lookup_const_by_id(tcx, def_id),
         _ => None
     }
 }
@@ -178,7 +178,7 @@ pub fn lookup_const_by_id(tcx: ty::ctxt,
         match tcx.items.find(&def_id.node) {
             None => None,
             Some(&ast_map::node_item(it, _)) => match it.node {
-                item_const(_, const_expr) => Some(const_expr),
+                item_static(_, ast::m_imm, const_expr) => Some(const_expr),
                 _ => None
             },
             Some(_) => None
@@ -195,7 +195,7 @@ pub fn lookup_const_by_id(tcx: ty::ctxt,
         match csearch::maybe_get_item_ast(tcx, def_id,
             |a, b, c, d| astencode::decode_inlined_item(a, b, maps, /*bar*/ copy c, d)) {
             csearch::found(ast::ii_item(item)) => match item.node {
-                item_const(_, const_expr) => Some(const_expr),
+                item_static(_, ast::m_imm, const_expr) => Some(const_expr),
                 _ => None
             },
             _ => None

src/librustc/middle/effect.rs

@@ -17,7 +17,7 @@ use middle::typeck::method_map;
 use util::ppaux;
 
 use syntax::ast::{deref, expr_call, expr_inline_asm, expr_method_call};
-use syntax::ast::{expr_unary, node_id, unsafe_blk, unsafe_fn};
+use syntax::ast::{expr_unary, node_id, unsafe_blk, unsafe_fn, expr_path};
 use syntax::ast;
 use syntax::codemap::span;
 use syntax::visit::{fk_item_fn, fk_method};
@@ -143,6 +143,14 @@ pub fn check_crate(tcx: ty::ctxt,
                 expr_inline_asm(*) => {
                     require_unsafe(expr.span, "use of inline assembly")
                 }
+                expr_path(*) => {
+                    match ty::resolve_expr(tcx, expr) {
+                        ast::def_static(_, true) => {
+                            require_unsafe(expr.span, "use of mutable static")
+                        }
+                        _ => {}
+                    }
+                }
                 _ => {}
             }
 

src/librustc/middle/lint.rs

@@ -709,40 +709,42 @@ fn check_item_default_methods(cx: &Context, item: @ast::item) {
 }
 
 fn check_item_ctypes(cx: &Context, it: @ast::item) {
+    fn check_ty(cx: &Context, ty: @ast::Ty) {
+        match ty.node {
+            ast::ty_path(_, _, id) => {
+                match cx.tcx.def_map.get_copy(&id) {
+                    ast::def_prim_ty(ast::ty_int(ast::ty_i)) => {
+                        cx.span_lint(ctypes, ty.span,
+                                "found rust type `int` in foreign module, while \
+                                libc::c_int or libc::c_long should be used");
+                    }
+                    ast::def_prim_ty(ast::ty_uint(ast::ty_u)) => {
+                        cx.span_lint(ctypes, ty.span,
+                                "found rust type `uint` in foreign module, while \
+                                libc::c_uint or libc::c_ulong should be used");
+                    }
+                    _ => ()
+                }
+            }
+            _ => ()
+        }
+    }
 
     fn check_foreign_fn(cx: &Context, decl: &ast::fn_decl) {
         let tys = vec::map(decl.inputs, |a| a.ty );
         for vec::each(vec::append_one(tys, decl.output)) |ty| {
-            match ty.node {
-              ast::ty_path(_, _, id) => {
-                match cx.tcx.def_map.get_copy(&id) {
-                  ast::def_prim_ty(ast::ty_int(ast::ty_i)) => {
-                    cx.span_lint(ctypes, ty.span,
-                        "found rust type `int` in foreign module, while \
-                         libc::c_int or libc::c_long should be used");
-                  }
-                  ast::def_prim_ty(ast::ty_uint(ast::ty_u)) => {
-                    cx.span_lint(ctypes, ty.span,
-                        "found rust type `uint` in foreign module, while \
-                         libc::c_uint or libc::c_ulong should be used");
-                  }
-                  _ => ()
-                }
-              }
-              _ => ()
-            }
+            check_ty(cx, *ty);
         }
     }
 
     match it.node {
       ast::item_foreign_mod(ref nmod) if !nmod.abis.is_intrinsic() => {
         for nmod.items.iter().advance |ni| {
             match ni.node {
-              ast::foreign_item_fn(ref decl, _, _) => {
-                check_foreign_fn(cx, decl);
-              }
-              // FIXME #4622: Not implemented.
-              ast::foreign_item_const(*) => {}
+                ast::foreign_item_fn(ref decl, _, _) => {
+                    check_foreign_fn(cx, decl);
+                }
+                ast::foreign_item_static(t, _) => { check_ty(cx, t); }
             }
         }
       }

src/librustc/middle/mem_categorization.rs

@@ -447,19 +447,29 @@ impl mem_categorization_ctxt {
                    -> cmt {
         match def {
           ast::def_fn(*) | ast::def_static_method(*) | ast::def_mod(_) |
-          ast::def_foreign_mod(_) | ast::def_const(_) |
+          ast::def_foreign_mod(_) | ast::def_static(_, false) |
           ast::def_use(_) | ast::def_variant(*) |
           ast::def_trait(_) | ast::def_ty(_) | ast::def_prim_ty(_) |
           ast::def_ty_param(*) | ast::def_struct(*) |
           ast::def_typaram_binder(*) | ast::def_region(_) |
           ast::def_label(_) | ast::def_self_ty(*) => {
-            @cmt_ {
-                id:id,
-                span:span,
-                cat:cat_static_item,
-                mutbl: McImmutable,
-                ty:expr_ty
-            }
+              @cmt_ {
+                  id:id,
+                  span:span,
+                  cat:cat_static_item,
+                  mutbl: McImmutable,
+                  ty:expr_ty
+              }
+          }
+
+          ast::def_static(_, true) => {
+              @cmt_ {
+                  id:id,
+                  span:span,
+                  cat:cat_static_item,
+                  mutbl: McDeclared,
+                  ty:expr_ty
+              }
           }
 
           ast::def_arg(vid, mutbl) => {
@@ -894,7 +904,7 @@ impl mem_categorization_ctxt {
                         self.cat_pattern(cmt_field, subpat, op);
                     }
                 }
-                Some(&ast::def_const(*)) => {
+                Some(&ast::def_static(*)) => {
                     for subpats.iter().advance |&subpat| {
                         self.cat_pattern(cmt, subpat, op);
                     }

src/librustc/middle/pat_util.rs

@@ -45,7 +45,7 @@ pub fn pat_is_const(dm: resolve::DefMap, pat: &pat) -> bool {
     match pat.node {
         pat_ident(_, _, None) | pat_enum(*) => {
             match dm.find(&pat.id) {
-                Some(&def_const(*)) => true,
+                Some(&def_static(_, false)) => true,
                 _ => false
             }
         }