From 0bb77bdb5423402b583372abf2f097be6b4e46bc Mon Sep 17 00:00:00 2001
From: Basile Desloges <basile.desloges@gmail.com>
Date: Sun, 12 Nov 2017 12:40:56 +0100
Subject: [PATCH] mir-borrowck: Move `is_static_mut()` to `ty/utils.rs`

---
 src/librustc/ty/util.rs                      | 23 +++++++++++++++++++-
 src/librustc_mir/transform/check_unsafety.rs | 23 ++------------------
 2 files changed, 24 insertions(+), 22 deletions(-)

diff --git a/src/librustc/ty/util.rs b/src/librustc/ty/util.rs
index d12a973017d..aa07a6b070e 100644
--- a/src/librustc/ty/util.rs
+++ b/src/librustc/ty/util.rs
@@ -10,8 +10,9 @@
 
 //! misc. type-system utilities too small to deserve their own file
 
+use hir::def::Def;
 use hir::def_id::{DefId, LOCAL_CRATE};
-use hir::map::DefPathData;
+use hir::map::{DefPathData, Node};
 use hir;
 use ich::NodeIdHashingMode;
 use middle::const_val::ConstVal;
@@ -648,6 +649,26 @@ pub fn const_usize(&self, val: u16) -> ConstInt {
             _ => bug!(),
         }
     }
+
+    /// Check if the node pointed to by def_id is a mutable static item
+    pub fn is_static_mut(&self, def_id: DefId) -> bool {
+        if let Some(node) = self.hir.get_if_local(def_id) {
+            match node {
+                Node::NodeItem(&hir::Item {
+                    node: hir::ItemStatic(_, hir::MutMutable, _), ..
+                }) => true,
+                Node::NodeForeignItem(&hir::ForeignItem {
+                    node: hir::ForeignItemStatic(_, mutbl), ..
+                }) => mutbl,
+                _ => false
+            }
+        } else {
+            match self.describe_def(def_id) {
+                Some(Def::Static(_, mutbl)) => mutbl,
+                _ => false
+            }
+        }
+    }
 }
 
 pub struct TypeIdHasher<'a, 'gcx: 'a+'tcx, 'tcx: 'a, W> {
diff --git a/src/librustc_mir/transform/check_unsafety.rs b/src/librustc_mir/transform/check_unsafety.rs
index 53a4b2551fd..cbf1b0b0899 100644
--- a/src/librustc_mir/transform/check_unsafety.rs
+++ b/src/librustc_mir/transform/check_unsafety.rs
@@ -14,9 +14,8 @@
 use rustc::ty::maps::Providers;
 use rustc::ty::{self, TyCtxt};
 use rustc::hir;
-use rustc::hir::def::Def;
 use rustc::hir::def_id::DefId;
-use rustc::hir::map::{DefPathData, Node};
+use rustc::hir::map::DefPathData;
 use rustc::lint::builtin::{SAFE_EXTERN_STATICS, UNUSED_UNSAFE};
 use rustc::mir::*;
 use rustc::mir::visit::{LvalueContext, Visitor};
@@ -189,7 +188,7 @@ fn visit_lvalue(&mut self,
                 // locals are safe
             }
             &Lvalue::Static(box Static { def_id, ty: _ }) => {
-                if self.is_static_mut(def_id) {
+                if self.tcx.is_static_mut(def_id) {
                     self.require_unsafe("use of mutable static");
                 } else if self.tcx.is_foreign_item(def_id) {
                     let source_info = self.source_info;
@@ -208,24 +207,6 @@ fn visit_lvalue(&mut self,
 }
 
 impl<'a, 'tcx> UnsafetyChecker<'a, 'tcx> {
-    fn is_static_mut(&self, def_id: DefId) -> bool {
-        if let Some(node) = self.tcx.hir.get_if_local(def_id) {
-            match node {
-                Node::NodeItem(&hir::Item {
-                    node: hir::ItemStatic(_, hir::MutMutable, _), ..
-                }) => true,
-                Node::NodeForeignItem(&hir::ForeignItem {
-                    node: hir::ForeignItemStatic(_, mutbl), ..
-                }) => mutbl,
-                _ => false
-            }
-        } else {
-            match self.tcx.describe_def(def_id) {
-                Some(Def::Static(_, mutbl)) => mutbl,
-                _ => false
-            }
-        }
-    }
     fn require_unsafe(&mut self,
                       description: &'static str)
     {