librustc: De-@mut llupvars in the translation crate context

src/librustc/middle/trans/base.rs

@@ -69,6 +69,7 @@
 use middle::trans::type_::Type;
 
 use std::c_str::ToCStr;
+use std::cell::RefCell;
 use std::hashmap::HashMap;
 use std::libc::c_uint;
 use std::vec;
@@ -1693,7 +1694,7 @@ pub fn new_fn_ctxt_w_id(ccx: @CrateContext,
           caller_expects_out_pointer: uses_outptr,
           llargs: @mut HashMap::new(),
           lllocals: @mut HashMap::new(),
-          llupvars: @mut HashMap::new(),
+          llupvars: RefCell::new(HashMap::new()),
           id: id,
           param_substs: param_substs,
           span: sp,

src/librustc/middle/trans/closure.rs

@@ -328,7 +328,11 @@ pub fn load_environment(fcx: @mut FunctionContext,
             ast::ManagedSigil | ast::OwnedSigil => {}
         }
         let def_id = ast_util::def_id_of_def(cap_var.def);
-        fcx.llupvars.insert(def_id.node, upvarptr);
+
+        {
+            let mut llupvars = fcx.llupvars.borrow_mut();
+            llupvars.get().insert(def_id.node, upvarptr);
+        }
 
         for &env_pointer_alloca in env_pointer_alloca.iter() {
             debuginfo::create_captured_var_metadata(

src/librustc/middle/trans/common.rs

@@ -245,7 +245,7 @@ pub struct FunctionContext {
     // them in llallocas.
     lllocals: @mut HashMap<ast::NodeId, ValueRef>,
     // Same as above, but for closure upvars
-    llupvars: @mut HashMap<ast::NodeId, ValueRef>,
+    llupvars: RefCell<HashMap<ast::NodeId, ValueRef>>,
 
     // The NodeId of the function, or -1 if it doesn't correspond to
     // a user-defined function.

src/librustc/middle/trans/expr.rs

@@ -1084,7 +1084,8 @@ pub fn trans_local_var(bcx: @Block, def: ast::Def) -> Datum {
         ast::DefUpvar(nid, _, _, _) => {
             // Can't move upvars, so this is never a ZeroMemLastUse.
             let local_ty = node_id_type(bcx, nid);
-            match bcx.fcx.llupvars.find(&nid) {
+            let llupvars = bcx.fcx.llupvars.borrow();
+            match llupvars.get().find(&nid) {
                 Some(&val) => {
                     Datum {
                         val: val,