rustc_typeck: do not mutate tables directly during upvar inference.

src/librustc/infer/mod.rs

@@ -1521,10 +1521,6 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> {
         !traits::type_known_to_meet_bound(self, param_env, ty, copy_def_id, span)
     }
 
-    pub fn upvar_capture(&self, upvar_id: ty::UpvarId) -> Option<ty::UpvarCapture<'tcx>> {
-        self.tables.borrow().upvar_capture_map.get(&upvar_id).cloned()
-    }
-
     pub fn closure_kind(&self,
                         def_id: DefId)
                         -> Option<ty::ClosureKind>

src/librustc/middle/expr_use_visitor.rs

@@ -270,23 +270,9 @@ impl<'a, 'gcx, 'tcx> ExprUseVisitor<'a, 'gcx, 'tcx> {
                infcx: &'a InferCtxt<'a, 'gcx, 'tcx>,
                param_env: ty::ParamEnv<'tcx>)
                -> Self
-    {
-        ExprUseVisitor::with_options(delegate,
-                                     infcx,
-                                     param_env,
-                                     region_maps,
-                                     mc::MemCategorizationOptions::default())
-    }
-
-    pub fn with_options(delegate: &'a mut (Delegate<'tcx>+'a),
-                        infcx: &'a InferCtxt<'a, 'gcx, 'tcx>,
-                        param_env: ty::ParamEnv<'tcx>,
-                        region_maps: &'a RegionMaps,
-                        options: mc::MemCategorizationOptions)
-               -> Self
     {
         ExprUseVisitor {
-            mc: mc::MemCategorizationContext::with_options(infcx, region_maps, options),
+            mc: mc::MemCategorizationContext::new(infcx, region_maps),
             delegate,
             param_env,
         }
@@ -678,8 +664,8 @@ impl<'a, 'gcx, 'tcx> ExprUseVisitor<'a, 'gcx, 'tcx> {
     // consumed or borrowed as part of the automatic adjustment
     // process.
     fn walk_adjustment(&mut self, expr: &hir::Expr) {
-        //NOTE(@jroesch): mixed RefCell borrow causes crash
-        let adjustments = self.mc.infcx.tables.borrow().expr_adjustments(expr).to_vec();
+        let tables = self.mc.infcx.tables.borrow();
+        let adjustments = tables.expr_adjustments(expr);
         let mut cmt = return_if_err!(self.mc.cat_expr_unadjusted(expr));
         for adjustment in adjustments {
             debug!("walk_adjustment expr={:?} adj={:?}", expr, adjustment);
@@ -896,7 +882,7 @@ impl<'a, 'gcx, 'tcx> ExprUseVisitor<'a, 'gcx, 'tcx> {
                 let id_var = self.tcx().hir.as_local_node_id(def_id).unwrap();
                 let upvar_id = ty::UpvarId { var_id: id_var,
                                              closure_expr_id: closure_expr.id };
-                let upvar_capture = self.mc.infcx.upvar_capture(upvar_id).unwrap();
+                let upvar_capture = self.mc.infcx.tables.borrow().upvar_capture(upvar_id);
                 let cmt_var = return_if_err!(self.cat_captured_var(closure_expr.id,
                                                                    fn_decl_span,
                                                                    freevar.def));

src/librustc/middle/mem_categorization.rs

@@ -283,18 +283,6 @@ impl ast_node for hir::Pat {
 pub struct MemCategorizationContext<'a, 'gcx: 'a+'tcx, 'tcx: 'a> {
     pub infcx: &'a InferCtxt<'a, 'gcx, 'tcx>,
     pub region_maps: &'a RegionMaps,
-    options: MemCategorizationOptions,
-}
-
-#[derive(Copy, Clone, Default)]
-pub struct MemCategorizationOptions {
-    // If true, then when analyzing a closure upvar, if the closure
-    // has a missing kind, we treat it like a Fn closure. When false,
-    // we ICE if the closure has a missing kind. Should be false
-    // except during closure kind inference. It is used by the
-    // mem-categorization code to be able to have stricter assertions
-    // (which are always true except during upvar inference).
-    pub during_closure_kind_inference: bool,
 }
 
 pub type McResult<T> = Result<T, ()>;
@@ -400,20 +388,7 @@ impl<'a, 'gcx, 'tcx> MemCategorizationContext<'a, 'gcx, 'tcx> {
     pub fn new(infcx: &'a InferCtxt<'a, 'gcx, 'tcx>,
                region_maps: &'a RegionMaps)
                -> MemCategorizationContext<'a, 'gcx, 'tcx> {
-        MemCategorizationContext::with_options(infcx,
-                                               region_maps,
-                                               MemCategorizationOptions::default())
-    }
-
-    pub fn with_options(infcx: &'a InferCtxt<'a, 'gcx, 'tcx>,
-                        region_maps: &'a RegionMaps,
-                        options: MemCategorizationOptions)
-                        -> MemCategorizationContext<'a, 'gcx, 'tcx> {
-        MemCategorizationContext {
-            infcx: infcx,
-            region_maps: region_maps,
-            options: options,
-        }
+        MemCategorizationContext { infcx, region_maps }
     }
 
     fn tcx(&self) -> TyCtxt<'a, 'gcx, 'tcx> {
@@ -620,38 +595,14 @@ impl<'a, 'gcx, 'tcx> MemCategorizationContext<'a, 'gcx, 'tcx> {
 
           Def::Upvar(def_id, _, fn_node_id) => {
               let var_id = self.tcx().hir.as_local_node_id(def_id).unwrap();
-              let ty = self.node_ty(fn_node_id)?;
-              match ty.sty {
-                  ty::TyClosure(closure_id, _) => {
-                      match self.infcx.closure_kind(closure_id) {
-                          Some(kind) => {
-                              self.cat_upvar(id, span, var_id, fn_node_id, kind)
-                          }
-                          None => {
-                              if !self.options.during_closure_kind_inference {
-                                  span_bug!(
-                                      span,
-                                      "No closure kind for {:?}",
-                                      closure_id);
-                              }
-
-                              // during closure kind inference, we
-                              // don't know the closure kind yet, but
-                              // it's ok because we detect that we are
-                              // accessing an upvar and handle that
-                              // case specially anyhow. Use Fn
-                              // arbitrarily.
-                              self.cat_upvar(id, span, var_id, fn_node_id, ty::ClosureKind::Fn)
-                          }
-                      }
-                  }
-                  _ => {
-                      span_bug!(
-                          span,
-                          "Upvar of non-closure {} - {:?}",
-                          fn_node_id,
-                          ty);
-                  }
+              let closure_id = self.tcx().hir.local_def_id(fn_node_id);
+              match self.infcx.closure_kind(closure_id) {
+                Some(kind) => {
+                    self.cat_upvar(id, span, var_id, fn_node_id, kind)
+                }
+                None => {
+                    span_bug!(span, "No closure kind for {:?}", closure_id);
+                }
               }
           }
 
@@ -743,7 +694,7 @@ impl<'a, 'gcx, 'tcx> MemCategorizationContext<'a, 'gcx, 'tcx> {
         // for that.
         let upvar_id = ty::UpvarId { var_id: var_id,
                                      closure_expr_id: fn_node_id };
-        let upvar_capture = self.infcx.upvar_capture(upvar_id).unwrap();
+        let upvar_capture = self.infcx.tables.borrow().upvar_capture(upvar_id);
         let cmt_result = match upvar_capture {
             ty::UpvarCapture::ByValue => {
                 cmt_result

src/librustc/ty/context.rs

@@ -376,8 +376,8 @@ impl<'tcx> TypeckTables<'tcx> {
         }
     }
 
-    pub fn upvar_capture(&self, upvar_id: ty::UpvarId) -> Option<ty::UpvarCapture<'tcx>> {
-        Some(self.upvar_capture_map.get(&upvar_id).unwrap().clone())
+    pub fn upvar_capture(&self, upvar_id: ty::UpvarId) -> ty::UpvarCapture<'tcx> {
+        self.upvar_capture_map[&upvar_id]
     }
 }
 

src/librustc_mir/build/mod.rs

@@ -365,13 +365,14 @@ fn construct_fn<'a, 'gcx, 'tcx, A>(hir: Cx<'a, 'gcx, 'tcx>,
     let upvar_decls: Vec<_> = tcx.with_freevars(fn_id, |freevars| {
         freevars.iter().map(|fv| {
             let var_id = tcx.hir.as_local_node_id(fv.def.def_id()).unwrap();
-            let by_ref = hir.tables().upvar_capture(ty::UpvarId {
+            let capture = hir.tables().upvar_capture(ty::UpvarId {
                 var_id: var_id,
                 closure_expr_id: fn_id
-            }).map_or(false, |capture| match capture {
+            });
+            let by_ref = match capture {
                 ty::UpvarCapture::ByValue => false,
                 ty::UpvarCapture::ByRef(..) => true
-            });
+            };
             let mut decl = UpvarDecl {
                 debug_name: keywords::Invalid.name(),
                 by_ref: by_ref

src/librustc_mir/hair/cx/expr.rs

@@ -758,13 +758,7 @@ fn convert_var<'a, 'gcx, 'tcx>(cx: &mut Cx<'a, 'gcx, 'tcx>,
                 var_id: id_var,
                 closure_expr_id: closure_expr_id,
             };
-            let upvar_capture = match cx.tables().upvar_capture(upvar_id) {
-                Some(c) => c,
-                None => {
-                    span_bug!(expr.span, "no upvar_capture for {:?}", upvar_id);
-                }
-            };
-            match upvar_capture {
+            match cx.tables().upvar_capture(upvar_id) {
                 ty::UpvarCapture::ByValue => field_kind,
                 ty::UpvarCapture::ByRef(borrow) => {
                     ExprKind::Deref {
@@ -878,7 +872,7 @@ fn capture_freevar<'a, 'gcx, 'tcx>(cx: &mut Cx<'a, 'gcx, 'tcx>,
         var_id: id_var,
         closure_expr_id: closure_expr.id,
     };
-    let upvar_capture = cx.tables().upvar_capture(upvar_id).unwrap();
+    let upvar_capture = cx.tables().upvar_capture(upvar_id);
     let temp_lifetime = cx.region_maps.temporary_scope(closure_expr.id);
     let var_ty = cx.tables().node_id_to_type(id_var);
     let captured_var = Expr {

src/librustc_typeck/check/regionck.rs

@@ -834,8 +834,8 @@ impl<'a, 'gcx, 'tcx> RegionCtxt<'a, 'gcx, 'tcx> {
             mc.cat_expr_unadjusted(expr)?
         };
 
-        //NOTE(@jroesch): mixed RefCell borrow causes crash
-        let adjustments = self.tables.borrow().expr_adjustments(&expr).to_vec();
+        let tables = self.tables.borrow();
+        let adjustments = tables.expr_adjustments(&expr);
         if adjustments.is_empty() {
             return Ok(cmt);
         }
@@ -1215,8 +1215,7 @@ impl<'a, 'gcx, 'tcx> RegionCtxt<'a, 'gcx, 'tcx> {
         // Detect by-ref upvar `x`:
         let cause = match note {
             mc::NoteUpvarRef(ref upvar_id) => {
-                let upvar_capture_map = &self.tables.borrow_mut().upvar_capture_map;
-                match upvar_capture_map.get(upvar_id) {
+                match self.tables.borrow().upvar_capture_map.get(upvar_id) {
                     Some(&ty::UpvarCapture::ByRef(ref upvar_borrow)) => {
                         // The mutability of the upvar may have been modified
                         // by the above adjustment, so update our local variable.