Convert Place's projection to a boxed slice

[rust.git] / src / librustc_mir / borrow_check / error_reporting.rs

diff --git a/src/librustc_mir/borrow_check/error_reporting.rs b/src/librustc_mir/borrow_check/error_reporting.rs
index 251d4b727c7544b35427d1b81e5e3e8db6bfd809..1fbedc49ecf3f62c09493555250ffddb36519b45 100644 (file)
--- a/src/librustc_mir/borrow_check/error_reporting.rs
+++ b/src/librustc_mir/borrow_check/error_reporting.rs
@@ -152,7 +152,7 @@ fn append_place_to_string(
         match place {
             PlaceRef {
                 base: PlaceBase::Local(local),
-                projection: None,
+                projection: [],
             } => {
                 self.append_local_to_string(*local, buf)?;
             }
@@ -162,7 +162,7 @@ fn append_place_to_string(
                         kind: StaticKind::Promoted(..),
                         ..
                     }),
-                projection: None,
+                projection: [],
             } => {
                 buf.push_str("promoted");
             }
@@ -173,15 +173,17 @@ fn append_place_to_string(
                         def_id,
                         ..
                     }),
-                projection: None,
+                projection: [],
             } => {
                 buf.push_str(&self.infcx.tcx.item_name(*def_id).to_string());
             }
             PlaceRef {
                 base,
-                projection: Some(ref proj),
+                projection: [.., elem],
             } => {
-                match proj.elem {
+                let proj_base = &place.projection[..place.projection.len() - 1];
+
+                match elem {
                     ProjectionElem::Deref => {
                         let upvar_field_projection =
                             self.is_upvar_field_projection(place);
@@ -199,20 +201,20 @@ fn append_place_to_string(
                                 self.append_place_to_string(
                                     PlaceRef {
                                         base,
-                                        projection: &proj.base,
+                                        projection: proj_base,
                                     },
                                     buf,
                                     autoderef,
                                     &including_downcast,
                                 )?;
                             } else {
-                                match (&proj.base, base) {
-                                    (None, PlaceBase::Local(local)) => {
+                                match (proj_base, base) {
+                                    ([], PlaceBase::Local(local)) => {
                                         if self.body.local_decls[*local].is_ref_for_guard() {
                                             self.append_place_to_string(
                                                 PlaceRef {
                                                     base,
-                                                    projection: &proj.base,
+                                                    projection: proj_base,
                                                 },
                                                 buf,
                                                 autoderef,
@@ -224,7 +226,7 @@ fn append_place_to_string(
                                             self.append_place_to_string(
                                                 PlaceRef {
                                                     base,
-                                                    projection: &proj.base,
+                                                    projection: proj_base,
                                                 },
                                                 buf,
                                                 autoderef,
@@ -238,7 +240,7 @@ fn append_place_to_string(
                                         self.append_place_to_string(
                                             PlaceRef {
                                                 base,
-                                                projection: &proj.base,
+                                                projection: proj_base,
                                             },
                                             buf,
                                             autoderef,
@@ -253,7 +255,7 @@ fn append_place_to_string(
                         self.append_place_to_string(
                             PlaceRef {
                                 base,
-                                projection: &proj.base,
+                                projection: proj_base,
                             },
                             buf,
                             autoderef,
@@ -275,12 +277,12 @@ fn append_place_to_string(
                         } else {
                             let field_name = self.describe_field(PlaceRef {
                                 base,
-                                projection: &proj.base,
-                            }, field);
+                                projection: proj_base,
+                            }, *field);
                             self.append_place_to_string(
                                 PlaceRef {
                                     base,
-                                    projection: &proj.base,
+                                    projection: proj_base,
                                 },
                                 buf,
                                 autoderef,
@@ -295,14 +297,14 @@ fn append_place_to_string(
                         self.append_place_to_string(
                             PlaceRef {
                                 base,
-                                projection: &proj.base,
+                                projection: proj_base,
                             },
                             buf,
                             autoderef,
                             &including_downcast,
                         )?;
                         buf.push_str("[");
-                        if self.append_local_to_string(index, buf).is_err() {
+                        if self.append_local_to_string(*index, buf).is_err() {
                             buf.push_str("_");
                         }
                         buf.push_str("]");
@@ -315,7 +317,7 @@ fn append_place_to_string(
                         self.append_place_to_string(
                             PlaceRef {
                                 base,
-                                projection: &proj.base,
+                                projection: proj_base,
                             },
                             buf,
                             autoderef,
@@ -336,7 +338,7 @@ fn append_local_to_string(&self, local_index: Local, buf: &mut String) -> Result
         let local = &self.body.local_decls[local_index];
         match local.name {
             Some(name) if !local.from_compiler_desugaring() => {
-                buf.push_str(name.as_str().get());
+                buf.push_str(&name.as_str());
                 Ok(())
             }
             _ => Err(()),
@@ -349,28 +351,32 @@ fn describe_field(&self, place: PlaceRef<'cx, 'tcx>, field: Field) -> String {
         match place {
             PlaceRef {
                 base: PlaceBase::Local(local),
-                projection: None,
+                projection: [],
             } => {
                 let local = &self.body.local_decls[*local];
                 self.describe_field_from_ty(&local.ty, field, None)
             }
             PlaceRef {
                 base: PlaceBase::Static(static_),
-                projection: None,
+                projection: [],
             } =>
                 self.describe_field_from_ty(&static_.ty, field, None),
             PlaceRef {
                 base,
-                projection: Some(proj),
-            } => match proj.elem {
-                ProjectionElem::Deref => self.describe_field(PlaceRef {
-                    base,
-                    projection: &proj.base,
-                }, field),
+                projection: [.., elem],
+            } => match elem {
+                ProjectionElem::Deref => {
+                    let proj_base = &place.projection[..place.projection.len() - 1];
+
+                    self.describe_field(PlaceRef {
+                        base,
+                        projection: proj_base,
+                    }, field)
+                }
                 ProjectionElem::Downcast(_, variant_index) => {
                     let base_ty =
                         Place::ty_from(place.base, place.projection, self.body, self.infcx.tcx).ty;
-                    self.describe_field_from_ty(&base_ty, field, Some(variant_index))
+                    self.describe_field_from_ty(&base_ty, field, Some(*variant_index))
                 }
                 ProjectionElem::Field(_, field_type) => {
                     self.describe_field_from_ty(&field_type, field, None)
@@ -378,9 +384,11 @@ fn describe_field(&self, place: PlaceRef<'cx, 'tcx>, field: Field) -> String {
                 ProjectionElem::Index(..)
                 | ProjectionElem::ConstantIndex { .. }
                 | ProjectionElem::Subslice { .. } => {
+                    let proj_base = &place.projection[..place.projection.len() - 1];
+
                     self.describe_field(PlaceRef {
                         base,
-                        projection: &proj.base,
+                        projection: proj_base,
                     }, field)
                 }
             },
@@ -445,7 +453,7 @@ pub fn is_place_thread_local(&self, place_ref: PlaceRef<'cx, 'tcx>) -> bool {
                 def_id,
                 ..
             }),
-            projection: None,
+            projection: [],
         } = place_ref {
             let attrs = self.infcx.tcx.get_attrs(*def_id);
             let is_thread_local = attrs.iter().any(|attr| attr.check_name(sym::thread_local));
@@ -830,7 +838,7 @@ pub(super) fn borrow_spans(&self, use_span: Span, location: Location) -> UseSpan
             Some(&Statement {
                 kind: StatementKind::Assign(Place {
                     base: PlaceBase::Local(local),
-                    projection: None,
+                    projection: box [],
                 }, _),
                 ..
             }) => local,