Fix Mir visitor macro to ensure it calls the proper method to invalidate the predecessors cache

Author: Nashenas88

src/librustc/mir/visit.rs

@@ -789,19 +789,31 @@ macro_rules! make_mir_visitor {
             }
 
             // Convenience methods
-
-            fn visit_location(&mut self, body: & $($mutability)? Body<'tcx>, location: Location) {
-                let basic_block = & $($mutability)? body[location.block];
-                if basic_block.statements.len() == location.statement_index {
-                    // TODO(nashenas88) how to ensure we clear the cache only in the mutable case...
-                    if let Some(ref $($mutability)? terminator) = basic_block.terminator {
-                        self.visit_terminator(terminator, location)
-                    }
-                } else {
-                    let statement = & $($mutability)?
-                        basic_block.statements[location.statement_index];
-                    self.visit_statement(statement, location)
+            make_mir_visitor!{@make_visit_location, $($mutability)?}
+        }
+    };
+    (@make_visit_location, mut) => {
+       fn visit_location(&mut self, body: &mut Body<'tcx>, location: Location) {
+          if body[location.block].statements.len() == location.statement_index {
+            if let Some(ref mut terminator) = body.basic_block_terminator_opt_mut(location.block) {
+                self.visit_terminator(terminator, location)
+            }
+          } else {
+            let statement = &mut body[location.block].statements[location.statement_index];
+            self.visit_statement(statement, location)
+          }
+       }
+    };
+    (@make_visit_location, ) => {
+        fn visit_location(&mut self, body: &Body<'tcx>, location: Location) {
+            let basic_block = &body[location.block];
+            if basic_block.statements.len() == location.statement_index {
+                if let Some(ref terminator) = basic_block.terminator_opt() {
+                    self.visit_terminator(terminator, location)
                 }
+            } else {
+                let statement = &basic_block.statements[location.statement_index];
+                self.visit_statement(statement, location)
             }
         }
     }