From 13f85cb097725a13ae24a6564c71597243b91c3d Mon Sep 17 00:00:00 2001
From: Patrick Walton <pcwalton@mimiga.net>
Date: Wed, 18 Dec 2013 17:00:56 -0800
Subject: [PATCH] librustc: De-`@mut` `CrateContext::vtables`.

---
 src/librustc/middle/trans/context.rs |  4 ++--
 src/librustc/middle/trans/meth.rs    | 13 +++++++++----
 2 files changed, 11 insertions(+), 6 deletions(-)

diff --git a/src/librustc/middle/trans/context.rs b/src/librustc/middle/trans/context.rs
index 3c3e92d00ad..c5253ab8d8d 100644
--- a/src/librustc/middle/trans/context.rs
+++ b/src/librustc/middle/trans/context.rs
@@ -69,7 +69,7 @@ pub struct CrateContext {
      monomorphized: RefCell<HashMap<mono_id, ValueRef>>,
      monomorphizing: RefCell<HashMap<ast::DefId, uint>>,
      // Cache generated vtables
-     vtables: HashMap<(ty::t, mono_id), ValueRef>,
+     vtables: RefCell<HashMap<(ty::t, mono_id), ValueRef>>,
      // Cache of constant strings,
      const_cstr_cache: HashMap<@str, ValueRef>,
 
@@ -196,7 +196,7 @@ impl CrateContext {
                   non_inlineable_statics: HashSet::new(),
                   monomorphized: RefCell::new(HashMap::new()),
                   monomorphizing: RefCell::new(HashMap::new()),
-                  vtables: HashMap::new(),
+                  vtables: RefCell::new(HashMap::new()),
                   const_cstr_cache: HashMap::new(),
                   const_globals: HashMap::new(),
                   const_values: HashMap::new(),
diff --git a/src/librustc/middle/trans/meth.rs b/src/librustc/middle/trans/meth.rs
index 8117d8e0bd5..a430c0b1a0b 100644
--- a/src/librustc/middle/trans/meth.rs
+++ b/src/librustc/middle/trans/meth.rs
@@ -539,9 +539,12 @@ pub fn get_vtable(bcx: @Block,
 
     // Check the cache.
     let hash_id = (self_ty, vtable_id(ccx, &origins[0]));
-    match ccx.vtables.find(&hash_id) {
-        Some(&val) => { return val }
-        None => { }
+    {
+        let vtables = ccx.vtables.borrow();
+        match vtables.get().find(&hash_id) {
+            Some(&val) => { return val }
+            None => { }
+        }
     }
 
     // Not in the cache. Actually build it.
@@ -559,7 +562,9 @@ pub fn get_vtable(bcx: @Block,
     glue::lazily_emit_all_tydesc_glue(ccx, tydesc);
 
     let vtable = make_vtable(ccx, tydesc, methods);
-    ccx.vtables.insert(hash_id, vtable);
+
+    let mut vtables = ccx.vtables.borrow_mut();
+    vtables.get().insert(hash_id, vtable);
     return vtable;
 }