Improved is_upvar_field_projection - no longer need recurse parameter.

4 files changed, 21 insertions, 19 deletions

diff --git a/src/librustc/mir/tcx.rs b/src/librustc/mir/tcx.rs
index c46f561e7b3..0359eb9b95d 100644
--- a/src/librustc/mir/tcx.rs
+++ b/src/librustc/mir/tcx.rs
@@ -125,9 +125,18 @@ impl<'tcx> Place<'tcx> {
     /// be `self` in the current MIR, because that is the only time we directly access the fields
     /// of a closure type.
     pub fn is_upvar_field_projection<'cx, 'gcx>(&self, mir: &'cx Mir<'tcx>,
-                                                tcx: &TyCtxt<'cx, 'gcx, 'tcx>,
-                                                recurse: bool) -> Option<Field> {
-        match *self {
+                                                tcx: &TyCtxt<'cx, 'gcx, 'tcx>) -> Option<Field> {
+        let place = if let Place::Projection(ref proj) = self {
+            if let ProjectionElem::Deref = proj.elem {
+                &proj.base
+            } else {
+                self
+            }
+        } else {
+            self
+        };
+
+        match place {
             Place::Projection(ref proj) => match proj.elem {
                 ProjectionElem::Field(field, _ty) => {
                     let base_ty = proj.base.ty(mir, *tcx).to_ty(*tcx);
@@ -138,13 +147,6 @@ impl<'tcx> Place<'tcx> {
                         None
                     }
                 },
-                ProjectionElem::Deref => {
-                    if recurse {
-                        proj.base.is_upvar_field_projection(mir, tcx, recurse)
-                    } else {
-                        None
-                    }
-                },
                 _ => None,
             },
             _ => None,
diff --git a/src/librustc_mir/borrow_check/error_reporting.rs b/src/librustc_mir/borrow_check/error_reporting.rs
index 9f5f1389c66..5dca01f8842 100644
--- a/src/librustc_mir/borrow_check/error_reporting.rs
+++ b/src/librustc_mir/borrow_check/error_reporting.rs
@@ -726,8 +726,8 @@ impl<'cx, 'gcx, 'tcx> MirBorrowckCtxt<'cx, 'gcx, 'tcx> {
             Place::Projection(ref proj) => {
                 match proj.elem {
                     ProjectionElem::Deref => {
-                        let upvar_field_projection = proj.base.is_upvar_field_projection(
-                            self.mir, &self.tcx, false);
+                        let upvar_field_projection = place.is_upvar_field_projection(
+                            self.mir, &self.tcx);
                         if let Some(field) = upvar_field_projection {
                             let var_index = field.index();
                             let name = self.mir.upvar_decls[var_index].debug_name.to_string();
@@ -788,7 +788,7 @@ impl<'cx, 'gcx, 'tcx> MirBorrowckCtxt<'cx, 'gcx, 'tcx> {
                         autoderef = true;
 
                         let upvar_field_projection = place.is_upvar_field_projection(
-                            self.mir, &self.tcx, false);
+                            self.mir, &self.tcx);
                         if let Some(field) = upvar_field_projection {
                             let var_index = field.index();
                             let name = self.mir.upvar_decls[var_index].debug_name.to_string();
diff --git a/src/librustc_mir/borrow_check/mod.rs b/src/librustc_mir/borrow_check/mod.rs
index f37052470c8..62bf2b0abe4 100644
--- a/src/librustc_mir/borrow_check/mod.rs
+++ b/src/librustc_mir/borrow_check/mod.rs
@@ -1215,7 +1215,7 @@ impl<'cx, 'gcx, 'tcx> MirBorrowckCtxt<'cx, 'gcx, 'tcx> {
                                 Operand::Move(ref place @ Place::Projection(_))
                                 | Operand::Copy(ref place @ Place::Projection(_)) => {
                                     if let Some(field) = place.is_upvar_field_projection(
-                                            self.mir, &self.tcx, false) {
+                                            self.mir, &self.tcx) {
                                         self.used_mut_upvars.push(field);
                                     }
                                 }
@@ -1804,7 +1804,7 @@ impl<'cx, 'gcx, 'tcx> MirBorrowckCtxt<'cx, 'gcx, 'tcx> {
                 place: place @ Place::Projection(_),
                 is_local_mutation_allowed: _,
             } => {
-                if let Some(field) = place.is_upvar_field_projection(self.mir, &self.tcx, false) {
+                if let Some(field) = place.is_upvar_field_projection(self.mir, &self.tcx) {
                     self.used_mut_upvars.push(field);
                 }
             }
@@ -1867,8 +1867,8 @@ impl<'cx, 'gcx, 'tcx> MirBorrowckCtxt<'cx, 'gcx, 'tcx> {
                                     // Mutably borrowed data is mutable, but only if we have a
                                     // unique path to the `&mut`
                                     hir::MutMutable => {
-                                        let mode = match proj.base.is_upvar_field_projection(
-                                            self.mir, &self.tcx, false)
+                                        let mode = match place.is_upvar_field_projection(
+                                            self.mir, &self.tcx)
                                         {
                                             Some(field)
                                                 if {
@@ -1914,7 +1914,7 @@ impl<'cx, 'gcx, 'tcx> MirBorrowckCtxt<'cx, 'gcx, 'tcx> {
                     | ProjectionElem::Subslice { .. }
                     | ProjectionElem::Downcast(..) => {
                         let upvar_field_projection = place.is_upvar_field_projection(
-                            self.mir, &self.tcx, false);
+                            self.mir, &self.tcx);
                         if let Some(field) = upvar_field_projection {
                             let decl = &self.mir.upvar_decls[field.index()];
                             debug!(
diff --git a/src/librustc_mir/borrow_check/nll/region_infer/error_reporting/mod.rs b/src/librustc_mir/borrow_check/nll/region_infer/error_reporting/mod.rs
index 93e8f3f8657..c7e28ceb140 100644
--- a/src/librustc_mir/borrow_check/nll/region_infer/error_reporting/mod.rs
+++ b/src/librustc_mir/borrow_check/nll/region_infer/error_reporting/mod.rs
@@ -175,7 +175,7 @@ impl<'tcx> RegionInferenceContext<'tcx> {
                     };
 
                     if initial_category == ConstraintCategory::Assignment
-                            && place.is_upvar_field_projection(mir, &infcx.tcx, true).is_some() {
+                            && place.is_upvar_field_projection(mir, &infcx.tcx).is_some() {
                         ConstraintCategory::AssignmentToUpvar
                     } else {
                         initial_category