From 42f7f7f437ad978dd95d3ec39a0f231d6cd161da Mon Sep 17 00:00:00 2001
From: Patrick Walton <pcwalton@mimiga.net>
Date: Thu, 19 Dec 2013 19:15:06 -0800
Subject: [PATCH] librustc: De-`@mut` `inherent_impls` in the type context

---
 src/librustc/metadata/encoder.rs           | 6 ++++--
 src/librustc/middle/dead.rs                | 3 ++-
 src/librustc/middle/ty.rs                  | 9 +++++----
 src/librustc/middle/typeck/check/method.rs | 3 ++-
 src/librustc/middle/typeck/coherence.rs    | 5 +++--
 5 files changed, 16 insertions(+), 10 deletions(-)

diff --git a/src/librustc/metadata/encoder.rs b/src/librustc/metadata/encoder.rs
index 35652e809c52..c04d7b1418fd 100644
--- a/src/librustc/metadata/encoder.rs
+++ b/src/librustc/metadata/encoder.rs
@@ -442,7 +442,8 @@ fn encode_reexported_static_base_methods(ecx: &EncodeContext,
                                          ebml_w: &mut writer::Encoder,
                                          exp: &middle::resolve::Export2)
                                          -> bool {
-    match ecx.tcx.inherent_impls.find(&exp.def_id) {
+    let inherent_impls = ecx.tcx.inherent_impls.borrow();
+    match inherent_impls.get().find(&exp.def_id) {
         Some(implementations) => {
             for &base_impl in implementations.iter() {
                 for &m in base_impl.methods.iter() {
@@ -862,7 +863,8 @@ fn should_inline(attrs: &[Attribute]) -> bool {
 fn encode_inherent_implementations(ecx: &EncodeContext,
                                    ebml_w: &mut writer::Encoder,
                                    def_id: DefId) {
-    match ecx.tcx.inherent_impls.find(&def_id) {
+    let inherent_impls = ecx.tcx.inherent_impls.borrow();
+    match inherent_impls.get().find(&def_id) {
         None => {}
         Some(&implementations) => {
             for implementation in implementations.iter() {
diff --git a/src/librustc/middle/dead.rs b/src/librustc/middle/dead.rs
index fe4da4181da3..dd4f92212d3b 100644
--- a/src/librustc/middle/dead.rs
+++ b/src/librustc/middle/dead.rs
@@ -282,7 +282,8 @@ impl DeadVisitor {
         // method of a private type is used, but the type itself is never
         // called directly.
         let def_id = local_def(id);
-        match self.tcx.inherent_impls.find(&def_id) {
+        let inherent_impls = self.tcx.inherent_impls.borrow();
+        match inherent_impls.get().find(&def_id) {
             None => (),
             Some(ref impl_list) => {
                 for impl_ in impl_list.iter() {
diff --git a/src/librustc/middle/ty.rs b/src/librustc/middle/ty.rs
index f3ba0feb37a9..976a4f3af68c 100644
--- a/src/librustc/middle/ty.rs
+++ b/src/librustc/middle/ty.rs
@@ -338,7 +338,7 @@ struct ctxt_ {
     // Maps a def_id of a type to a list of its inherent impls.
     // Contains implementations of methods that are inherent to a type.
     // Methods in these implementations don't need to be exported.
-    inherent_impls: @mut HashMap<ast::DefId, @mut ~[@Impl]>,
+    inherent_impls: RefCell<HashMap<ast::DefId, @mut ~[@Impl]>>,
 
     // Maps a def_id of an impl to an Impl structure.
     // Note that this contains all of the impls that we know about,
@@ -1006,7 +1006,7 @@ pub fn mk_ctxt(s: session::Session,
         destructor_for_type: RefCell::new(HashMap::new()),
         destructors: RefCell::new(HashSet::new()),
         trait_impls: RefCell::new(HashMap::new()),
-        inherent_impls:  @mut HashMap::new(),
+        inherent_impls: RefCell::new(HashMap::new()),
         impls:  @mut HashMap::new(),
         used_unsafe: @mut HashSet::new(),
         used_mut_nodes: @mut HashSet::new(),
@@ -4549,10 +4549,11 @@ pub fn populate_implementations_for_type_if_necessary(tcx: ctxt,
         // If this is an inherent implementation, record it.
         if associated_traits.is_none() {
             let implementation_list;
-            match tcx.inherent_impls.find(&type_id) {
+            let mut inherent_impls = tcx.inherent_impls.borrow_mut();
+            match inherent_impls.get().find(&type_id) {
                 None => {
                     implementation_list = @mut ~[];
-                    tcx.inherent_impls.insert(type_id, implementation_list);
+                    inherent_impls.get().insert(type_id, implementation_list);
                 }
                 Some(&existing_implementation_list) => {
                     implementation_list = existing_implementation_list;
diff --git a/src/librustc/middle/typeck/check/method.rs b/src/librustc/middle/typeck/check/method.rs
index f2222dba6977..2892ad62b736 100644
--- a/src/librustc/middle/typeck/check/method.rs
+++ b/src/librustc/middle/typeck/check/method.rs
@@ -527,7 +527,8 @@ impl<'a> LookupContext<'a> {
         // metadata if necessary.
         ty::populate_implementations_for_type_if_necessary(self.tcx(), did);
 
-        let opt_impl_infos = self.tcx().inherent_impls.find(&did);
+        let inherent_impls = self.tcx().inherent_impls.borrow();
+        let opt_impl_infos = inherent_impls.get().find(&did);
         for impl_infos in opt_impl_infos.iter() {
             for impl_info in impl_infos.iter() {
                 self.push_candidates_from_impl(
diff --git a/src/librustc/middle/typeck/coherence.rs b/src/librustc/middle/typeck/coherence.rs
index d9c053fa57e7..f4ffd03cf641 100644
--- a/src/librustc/middle/typeck/coherence.rs
+++ b/src/librustc/middle/typeck/coherence.rs
@@ -384,10 +384,11 @@ impl CoherenceChecker {
                              implementation: @Impl) {
         let tcx = self.crate_context.tcx;
         let implementation_list;
-        match tcx.inherent_impls.find(&base_def_id) {
+        let mut inherent_impls = tcx.inherent_impls.borrow_mut();
+        match inherent_impls.get().find(&base_def_id) {
             None => {
                 implementation_list = @mut ~[];
-                tcx.inherent_impls.insert(base_def_id, implementation_list);
+                inherent_impls.get().insert(base_def_id, implementation_list);
             }
             Some(&existing_implementation_list) => {
                 implementation_list = existing_implementation_list;