rustc: remove closure ID from Res::Upvar.

Author: eddyb

src/librustc/hir/def.rs

@@ -139,8 +139,7 @@ pub enum Res<Id = hir::HirId> {
     // Value namespace
     SelfCtor(DefId /* impl */),  // `DefId` refers to the impl
     Local(Id),
-    Upvar(Id,           // `HirId` of closed over local
-          ast::NodeId), // expr node that creates the closure
+    Upvar(Id),
 
     // Macro namespace
     NonMacroAttr(NonMacroAttrKind), // e.g., `#[inline]` or `#[rustfmt::skip]`
@@ -396,7 +395,7 @@ impl<Id> Res<Id> {
             Res::SelfCtor(id) => Res::SelfCtor(id),
             Res::PrimTy(id) => Res::PrimTy(id),
             Res::Local(id) => Res::Local(map(id)),
-            Res::Upvar(id, closure) => Res::Upvar(map(id), closure),
+            Res::Upvar(id) => Res::Upvar(map(id)),
             Res::SelfTy(a, b) => Res::SelfTy(a, b),
             Res::ToolMod => Res::ToolMod,
             Res::NonMacroAttr(attr_kind) => Res::NonMacroAttr(attr_kind),

src/librustc/middle/expr_use_visitor.rs

@@ -971,15 +971,13 @@ impl<'a, 'gcx, 'tcx> ExprUseVisitor<'a, 'gcx, 'tcx> {
                         -> mc::McResult<mc::cmt_<'tcx>> {
         // Create the cmt for the variable being borrowed, from the
         // caller's perspective
-        if upvar.has_parent {
-            let closure_def_id = self.tcx().hir().local_def_id_from_hir_id(closure_hir_id);
-            assert_eq!(self.mc.body_owner, self.tcx().parent(closure_def_id).unwrap());
-            let var_nid = self.tcx().hir().hir_to_node_id(var_id);
-            self.mc.cat_upvar(closure_hir_id, closure_span, var_nid)
+        let res = if upvar.has_parent {
+            Res::Upvar(var_id)
         } else {
-            let var_ty = self.mc.node_ty(var_id)?;
-            self.mc.cat_res(closure_hir_id, closure_span, var_ty, Res::Local(var_id))
-        }
+            Res::Local(var_id)
+        };
+        let var_ty = self.mc.node_ty(var_id)?;
+        self.mc.cat_res(closure_hir_id, closure_span, var_ty, res)
     }
 }
 

src/librustc/middle/mem_categorization.rs

@@ -78,6 +78,7 @@ use syntax_pos::Span;
 use std::borrow::Cow;
 use std::fmt;
 use std::hash::{Hash, Hasher};
+use rustc_data_structures::fx::FxIndexMap;
 use rustc_data_structures::indexed_vec::Idx;
 use std::rc::Rc;
 use crate::util::nodemap::ItemLocalSet;
@@ -289,6 +290,7 @@ impl HirNode for hir::Pat {
 pub struct MemCategorizationContext<'a, 'gcx: 'a+'tcx, 'tcx: 'a> {
     pub tcx: TyCtxt<'a, 'gcx, 'tcx>,
     pub body_owner: DefId,
+    pub upvars: Option<&'tcx FxIndexMap<hir::HirId, hir::Upvar>>,
     pub region_scope_tree: &'a region::ScopeTree,
     pub tables: &'a ty::TypeckTables<'tcx>,
     rvalue_promotable_map: Option<&'tcx ItemLocalSet>,
@@ -407,6 +409,7 @@ impl<'a, 'tcx> MemCategorizationContext<'a, 'tcx, 'tcx> {
         MemCategorizationContext {
             tcx,
             body_owner,
+            upvars: tcx.upvars(body_owner),
             region_scope_tree,
             tables,
             rvalue_promotable_map,
@@ -441,6 +444,7 @@ impl<'a, 'gcx, 'tcx> MemCategorizationContext<'a, 'gcx, 'tcx> {
         MemCategorizationContext {
             tcx,
             body_owner,
+            upvars: tcx.upvars(body_owner),
             region_scope_tree,
             tables,
             rvalue_promotable_map,
@@ -742,21 +746,20 @@ impl<'a, 'gcx, 'tcx> MemCategorizationContext<'a, 'gcx, 'tcx> {
                 })
             }
 
-            Res::Upvar(var_id, closure_node_id) => {
+            Res::Upvar(var_id) => {
+                assert!(self.upvars.map_or(false, |upvars| upvars.contains_key(&var_id)));
                 let var_nid = self.tcx.hir().hir_to_node_id(var_id);
-                let closure_def_id = self.tcx.hir().local_def_id(closure_node_id);
-                assert_eq!(self.body_owner, closure_def_id);
-
                 self.cat_upvar(hir_id, span, var_nid)
             }
 
-            Res::Local(vid) => {
-                let vnid = self.tcx.hir().hir_to_node_id(vid);
+            Res::Local(var_id) => {
+                assert!(!self.upvars.map_or(false, |upvars| upvars.contains_key(&var_id)));
+                let var_nid = self.tcx.hir().hir_to_node_id(var_id);
                 Ok(cmt_ {
                     hir_id,
                     span,
-                    cat: Categorization::Local(vid),
-                    mutbl: MutabilityCategory::from_local(self.tcx, self.tables, vnid),
+                    cat: Categorization::Local(var_id),
+                    mutbl: MutabilityCategory::from_local(self.tcx, self.tables, var_nid),
                     ty: expr_ty,
                     note: NoteNone
                 })
@@ -768,7 +771,7 @@ impl<'a, 'gcx, 'tcx> MemCategorizationContext<'a, 'gcx, 'tcx> {
 
     // Categorize an upvar, complete with invisible derefs of closure
     // environment and upvar reference as appropriate.
-    pub fn cat_upvar(
+    fn cat_upvar(
         &self,
         hir_id: hir::HirId,
         span: Span,

src/librustc_mir/hair/cx/expr.rs

@@ -960,11 +960,15 @@ fn convert_path_expr<'a, 'gcx, 'tcx>(cx: &mut Cx<'a, 'gcx, 'tcx>,
 
         Res::Def(DefKind::Static, id) => ExprKind::StaticRef { id },
 
-        Res::Local(var_hir_id) => convert_var(cx, expr, var_hir_id),
-        Res::Upvar(var_hir_id, closure_node_id) => {
-            let closure_def_id = cx.tcx.hir().local_def_id(closure_node_id);
-            assert_eq!(cx.body_owner, closure_def_id);
-            assert!(cx.tables().upvar_list[&cx.body_owner].contains_key(&var_hir_id));
+        Res::Local(var_hir_id) => {
+            assert!(!cx.tables().upvar_list.get(&cx.body_owner)
+                .map_or(false, |upvars| upvars.contains_key(&var_hir_id)));
+
+            convert_var(cx, expr, var_hir_id)
+        }
+        Res::Upvar(var_hir_id) => {
+            assert!(cx.tables().upvar_list.get(&cx.body_owner)
+                .map_or(false, |upvars| upvars.contains_key(&var_hir_id)));
 
             convert_var(cx, expr, var_hir_id)
         }

src/librustc_resolve/lib.rs

@@ -4053,7 +4053,7 @@ impl<'a> Resolver<'a> {
                                 Res::Upvar(..) => true,
                                 _ => false,
                             };
-                            res = Res::Upvar(var_id, function_id);
+                            res = Res::Upvar(var_id);
 
                             match self.upvars.entry(function_id).or_default().entry(var_id) {
                                 indexmap::map::Entry::Occupied(_) => continue,