Setup a different visit place set of methods for mutable and immutable visitors

In particular, use a blank visit_place for mutable visitor to be sure,
non modified visitors are not trying to mutating place.

Author: spastorino

src/librustc/mir/visit.rs

@@ -158,22 +158,7 @@ macro_rules! make_mir_visitor {
                 self.super_place_base(base, context, location);
             }
 
-            fn visit_projection(&mut self,
-                                base: & $($mutability)? PlaceBase<'tcx>,
-                                projection: & $($mutability)? [PlaceElem<'tcx>],
-                                context: PlaceContext,
-                                location: Location) {
-                self.super_projection(base, projection, context, location);
-            }
-
-            fn visit_projection_elem(&mut self,
-                                     base: & $($mutability)? PlaceBase<'tcx>,
-                                     proj_base: & $($mutability)? [PlaceElem<'tcx>],
-                                     elem: & $($mutability)? PlaceElem<'tcx>,
-                                     context: PlaceContext,
-                                     location: Location) {
-                self.super_projection_elem(base, proj_base, elem, context, location);
-            }
+            visit_place_fns!($($mutability)?);
 
             fn visit_constant(&mut self,
                               constant: & $($mutability)? Constant<'tcx>,
@@ -681,28 +666,6 @@ macro_rules! make_mir_visitor {
                 );
             }
 
-            fn super_place(&mut self,
-                            place: & $($mutability)? Place<'tcx>,
-                            context: PlaceContext,
-                            location: Location) {
-                let mut context = context;
-
-                if !place.projection.is_empty() {
-                    context = if context.is_mutating_use() {
-                        PlaceContext::MutatingUse(MutatingUseContext::Projection)
-                    } else {
-                        PlaceContext::NonMutatingUse(NonMutatingUseContext::Projection)
-                    };
-                }
-
-                self.visit_place_base(& $($mutability)? place.base, context, location);
-
-                self.visit_projection(& $($mutability)? place.base,
-                                      & $($mutability)? place.projection,
-                                      context,
-                                      location);
-            }
-
             fn super_place_base(&mut self,
                                 place_base: & $($mutability)? PlaceBase<'tcx>,
                                 context: PlaceContext,
@@ -717,45 +680,6 @@ macro_rules! make_mir_visitor {
                 }
             }
 
-            fn super_projection(&mut self,
-                                base: & $($mutability)? PlaceBase<'tcx>,
-                                projection: & $($mutability)? [PlaceElem<'tcx>],
-                                context: PlaceContext,
-                                location: Location) {
-                let mut cursor = projection;
-                while let [proj_base @ .., elem] = cursor {
-                    cursor = proj_base;
-                    self.visit_projection_elem(base, cursor, elem, context, location);
-                }
-            }
-
-            fn super_projection_elem(&mut self,
-                                     _base: & $($mutability)? PlaceBase<'tcx>,
-                                     _proj_base: & $($mutability)? [PlaceElem<'tcx>],
-                                     elem: & $($mutability)? PlaceElem<'tcx>,
-                                     _context: PlaceContext,
-                                     location: Location) {
-                match elem {
-                    ProjectionElem::Field(_field, ty) => {
-                        self.visit_ty(ty, TyContext::Location(location));
-                    }
-                    ProjectionElem::Index(local) => {
-                        self.visit_local(
-                            local,
-                            PlaceContext::NonMutatingUse(NonMutatingUseContext::Copy),
-                            location
-                        );
-                    }
-                    ProjectionElem::Deref |
-                    ProjectionElem::Subslice { from: _, to: _ } |
-                    ProjectionElem::ConstantIndex { offset: _,
-                                                    min_length: _,
-                                                    from_end: _ } |
-                    ProjectionElem::Downcast(_, _) => {
-                    }
-                }
-            }
-
             fn super_local_decl(&mut self,
                                 local: Local,
                                 local_decl: & $($mutability)? LocalDecl<'tcx>) {
@@ -858,6 +782,108 @@ macro_rules! make_mir_visitor {
     }
 }
 
+macro_rules! visit_place_fns {
+    (mut) => (
+        fn super_place(
+            &mut self,
+            _place: &mut Place<'tcx>,
+            _context: PlaceContext,
+            _location: Location,
+        ) {
+        }
+    );
+
+    () => (
+        fn visit_projection(
+            &mut self,
+            base: &PlaceBase<'tcx>,
+            projection: &[PlaceElem<'tcx>],
+            context: PlaceContext,
+            location: Location,
+        ) {
+            self.super_projection(base, projection, context, location);
+        }
+
+        fn visit_projection_elem(
+            &mut self,
+            base: &PlaceBase<'tcx>,
+            proj_base: &[PlaceElem<'tcx>],
+            elem: &PlaceElem<'tcx>,
+            context: PlaceContext,
+            location: Location,
+        ) {
+            self.super_projection_elem(base, proj_base, elem, context, location);
+        }
+
+        fn super_place(
+            &mut self,
+            place: &Place<'tcx>,
+            context: PlaceContext,
+            location: Location,
+        ) {
+            let mut context = context;
+
+            if !place.projection.is_empty() {
+                context = if context.is_mutating_use() {
+                    PlaceContext::MutatingUse(MutatingUseContext::Projection)
+                } else {
+                    PlaceContext::NonMutatingUse(NonMutatingUseContext::Projection)
+                };
+            }
+
+            self.visit_place_base(&place.base, context, location);
+
+            self.visit_projection(&place.base,
+                                  &place.projection,
+                                  context,
+                                  location);
+        }
+
+        fn super_projection(
+            &mut self,
+            base: &PlaceBase<'tcx>,
+            projection: &[PlaceElem<'tcx>],
+            context: PlaceContext,
+            location: Location,
+        ) {
+            let mut cursor = projection;
+            while let [proj_base @ .., elem] = cursor {
+                cursor = proj_base;
+                self.visit_projection_elem(base, cursor, elem, context, location);
+            }
+        }
+
+        fn super_projection_elem(
+            &mut self,
+            _base: &PlaceBase<'tcx>,
+            _proj_base: &[PlaceElem<'tcx>],
+            elem: &PlaceElem<'tcx>,
+            _context: PlaceContext,
+            location: Location,
+        ) {
+            match elem {
+                ProjectionElem::Field(_field, ty) => {
+                    self.visit_ty(ty, TyContext::Location(location));
+                }
+                ProjectionElem::Index(local) => {
+                    self.visit_local(
+                        local,
+                        PlaceContext::NonMutatingUse(NonMutatingUseContext::Copy),
+                        location
+                    );
+                }
+                ProjectionElem::Deref |
+                ProjectionElem::Subslice { from: _, to: _ } |
+                ProjectionElem::ConstantIndex { offset: _,
+                                                min_length: _,
+                                                from_end: _ } |
+                ProjectionElem::Downcast(_, _) => {
+                }
+            }
+        }
+    );
+}
+
 make_mir_visitor!(Visitor,);
 make_mir_visitor!(MutVisitor,mut);