Pass ImmTy by reference not value

compiler/rustc_mir/src/interpret/cast.rs

@@ -32,7 +32,7 @@ pub fn cast(
 
             Misc => {
                 let src = self.read_immediate(src)?;
-                let res = self.misc_cast(src, cast_ty)?;
+                let res = self.misc_cast(&src, cast_ty)?;
                 self.write_immediate(res, dest)?;
             }
 
@@ -107,7 +107,7 @@ pub fn cast(
 
     fn misc_cast(
         &self,
-        src: ImmTy<'tcx, M::PointerTag>,
+        src: &ImmTy<'tcx, M::PointerTag>,
         cast_ty: Ty<'tcx>,
     ) -> InterpResult<'tcx, Immediate<M::PointerTag>> {
         use rustc_middle::ty::TyKind::*;
@@ -158,13 +158,13 @@ fn misc_cast(
             let dest_layout = self.layout_of(cast_ty)?;
             if dest_layout.size == src.layout.size {
                 // Thin or fat pointer that just hast the ptr kind of target type changed.
-                return Ok(*src);
+                return Ok(**src);
             } else {
                 // Casting the metadata away from a fat ptr.
                 assert_eq!(src.layout.size, 2 * self.memory.pointer_size());
                 assert_eq!(dest_layout.size, self.memory.pointer_size());
                 assert!(src.layout.ty.is_unsafe_ptr());
-                return match *src {
+                return match **src {
                     Immediate::ScalarPair(data, _) => Ok(data.into()),
                     Immediate::Scalar(..) => span_bug!(
                         self.cur_span(),

compiler/rustc_mir/src/interpret/intern.rs

@@ -198,7 +198,7 @@ fn visit_value(&mut self, mplace: &MPlaceTy<'tcx>) -> InterpResult<'tcx> {
         let ty = mplace.layout.ty;
         if let ty::Ref(_, referenced_ty, ref_mutability) = *ty.kind() {
             let value = self.ecx.read_immediate(&(*mplace).into())?;
-            let mplace = self.ecx.ref_to_mplace(value)?;
+            let mplace = self.ecx.ref_to_mplace(&value)?;
             assert_eq!(mplace.layout.ty, referenced_ty);
             // Handle trait object vtables.
             if let ty::Dynamic(..) =

compiler/rustc_mir/src/interpret/intrinsics.rs

@@ -143,7 +143,7 @@ pub fn emulate_intrinsic(
             sym::min_align_of_val | sym::size_of_val => {
                 // Avoid `deref_operand` -- this is not a deref, the ptr does not have to be
                 // dereferencable!
-                let place = self.ref_to_mplace(self.read_immediate(&args[0])?)?;
+                let place = self.ref_to_mplace(&self.read_immediate(&args[0])?)?;
                 let (size, align) = self
                     .size_and_align_of_mplace(place)?
                     .ok_or_else(|| err_unsup_format!("`extern type` does not have known layout"))?;

compiler/rustc_mir/src/interpret/place.rs

@@ -303,12 +303,12 @@ impl<'mir, 'tcx: 'mir, Tag, M> InterpCx<'mir, 'tcx, M>
     /// Generally prefer `deref_operand`.
     pub fn ref_to_mplace(
         &self,
-        val: ImmTy<'tcx, M::PointerTag>,
+        val: &ImmTy<'tcx, M::PointerTag>,
     ) -> InterpResult<'tcx, MPlaceTy<'tcx, M::PointerTag>> {
         let pointee_type =
             val.layout.ty.builtin_deref(true).expect("`ref_to_mplace` called on non-ptr type").ty;
         let layout = self.layout_of(pointee_type)?;
-        let (ptr, meta) = match *val {
+        let (ptr, meta) = match **val {
             Immediate::Scalar(ptr) => (ptr.check_init()?, MemPlaceMeta::None),
             Immediate::ScalarPair(ptr, meta) => {
                 (ptr.check_init()?, MemPlaceMeta::Meta(meta.check_init()?))
@@ -335,7 +335,7 @@ pub fn deref_operand(
     ) -> InterpResult<'tcx, MPlaceTy<'tcx, M::PointerTag>> {
         let val = self.read_immediate(src)?;
         trace!("deref to {} on {:?}", val.layout.ty, *val);
-        let place = self.ref_to_mplace(val)?;
+        let place = self.ref_to_mplace(&val)?;
         self.mplace_access_checked(place, None)
     }
 

compiler/rustc_mir/src/interpret/validity.rs

@@ -386,7 +386,7 @@ fn check_safe_pointer(
         // Handle wide pointers.
         // Check metadata early, for better diagnostics
         let place = try_validation!(
-            self.ecx.ref_to_mplace(value),
+            self.ecx.ref_to_mplace(&value),
             self.path,
             err_ub!(InvalidUninitBytes(None)) => { "uninitialized {}", kind },
         );