From 7ffba5c3e16291b8bcadbe9485de8faad1766aa8 Mon Sep 17 00:00:00 2001
From: Patrick Walton <pcwalton@mimiga.net>
Date: Thu, 19 Dec 2013 20:20:04 -0800
Subject: [PATCH] librustc: De-`@mut` `llupvars` in the translation crate
 context

---
 src/librustc/middle/trans/base.rs    | 3 ++-
 src/librustc/middle/trans/closure.rs | 6 +++++-
 src/librustc/middle/trans/common.rs  | 2 +-
 src/librustc/middle/trans/expr.rs    | 3 ++-
 4 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/src/librustc/middle/trans/base.rs b/src/librustc/middle/trans/base.rs
index 6fe1f66dcfde..e02e8e4682b5 100644
--- a/src/librustc/middle/trans/base.rs
+++ b/src/librustc/middle/trans/base.rs
@@ -69,6 +69,7 @@ use util::sha2::Sha256;
 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,
diff --git a/src/librustc/middle/trans/closure.rs b/src/librustc/middle/trans/closure.rs
index 6e29d3c1ee2e..2fc821f53269 100644
--- a/src/librustc/middle/trans/closure.rs
+++ b/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(
diff --git a/src/librustc/middle/trans/common.rs b/src/librustc/middle/trans/common.rs
index 4a2ea244e009..d08917d0db03 100644
--- a/src/librustc/middle/trans/common.rs
+++ b/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.
diff --git a/src/librustc/middle/trans/expr.rs b/src/librustc/middle/trans/expr.rs
index cf6fca23c96b..cb3c8f408249 100644
--- a/src/librustc/middle/trans/expr.rs
+++ b/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,