Rollup merge of #65763 - ObsidianMinor:diag/65642, r=varkor

[rust.git] / src / librustc_mir / util / def_use.rs

diff --git a/src/librustc_mir/util/def_use.rs b/src/librustc_mir/util/def_use.rs
index 3aea25fa8769fe708623e42c8b86a97c97ee9f7b..cdd07ad4b8ff4b88ba81689ddbf0aca0b71a7055 100644 (file)
--- a/src/librustc_mir/util/def_use.rs
+++ b/src/librustc_mir/util/def_use.rs
@@ -1,6 +1,6 @@
 //! Def-use analysis.
 
-use rustc::mir::{Local, Location, Body};
+use rustc::mir::{Body, Local, Location, PlaceElem};
 use rustc::mir::visit::{PlaceContext, MutVisitor, Visitor};
 use rustc_index::vec::IndexVec;
 use std::mem;
@@ -47,13 +47,10 @@ pub fn local_info(&self, local: Local) -> &Info {
         &self.info[local]
     }
 
-    fn mutate_defs_and_uses<F>(&self, local: Local, body: &mut Body<'_>, mut callback: F)
-                               where F: for<'a> FnMut(&'a mut Local,
-                                                      PlaceContext,
-                                                      Location) {
+    fn mutate_defs_and_uses(&self, local: Local, body: &mut Body<'_>, new_local: Local) {
         for place_use in &self.info[local].defs_and_uses {
             MutateUseVisitor::new(local,
-                                  &mut callback,
+                                  new_local,
                                   body).visit_location(body, place_use.location)
         }
     }
@@ -63,7 +60,7 @@ pub fn replace_all_defs_and_uses_with(&self,
                                           local: Local,
                                           body: &mut Body<'_>,
                                           new_local: Local) {
-        self.mutate_defs_and_uses(local, body, |local, _, _| *local = new_local)
+        self.mutate_defs_and_uses(local, body, new_local)
     }
 }
 
@@ -117,30 +114,39 @@ pub fn use_count(&self) -> usize {
     }
 }
 
-struct MutateUseVisitor<F> {
+struct MutateUseVisitor {
     query: Local,
-    callback: F,
+    new_local: Local,
 }
 
-impl<F> MutateUseVisitor<F> {
-    fn new(query: Local, callback: F, _: &Body<'_>)
-           -> MutateUseVisitor<F>
-           where F: for<'a> FnMut(&'a mut Local, PlaceContext, Location) {
+impl MutateUseVisitor {
+    fn new(query: Local, new_local: Local, _: &Body<'_>) -> MutateUseVisitor {
         MutateUseVisitor {
             query,
-            callback,
+            new_local,
         }
     }
 }
 
-impl<F> MutVisitor<'_> for MutateUseVisitor<F>
-              where F: for<'a> FnMut(&'a mut Local, PlaceContext, Location) {
+impl MutVisitor<'_> for MutateUseVisitor {
     fn visit_local(&mut self,
                     local: &mut Local,
-                    context: PlaceContext,
-                    location: Location) {
+                    _context: PlaceContext,
+                    _location: Location) {
         if *local == self.query {
-            (self.callback)(local, context, location)
+            *local = self.new_local;
+        }
+    }
+
+    fn process_projection_elem(
+        &mut self,
+        elem: &PlaceElem<'tcx>,
+    ) -> Option<PlaceElem<'tcx>> {
+        match elem {
+            PlaceElem::Index(local) if *local == self.query => {
+                Some(PlaceElem::Index(self.new_local))
+            }
+            _ => None,
         }
     }
 }