Auto merge of #55665 - eddyb:by-ref-layout-of, r=oli-obk

rustc_target: pass contexts by reference, not value.

`LayoutOf` now takes `&self` instead of `self`, and so does every method generic over a context that implements `LayoutOf` and/or other traits, like `HasDataLayout`, `HasTyCtxt`, etc.

Originally using by-value `Copy` types was relevant because `TyCtxt` was one of those types, but now `TyCtxt::layout_of` is separate from `LayoutOf`, and `TyCtxt` is not an often used layout context.

Passing these context by reference is a lot nicer for miri, which has `self: &mut EvalContext`, and needed `f(&self)` (that is, creating `&&mut EvalContext` references) for layout purposes.
Now, the `&mut EvalContext` can be passed to a function expecting `&C`, directly.

This should help with #54012 / #55627 (to not need `where &'a T::Cx: LayoutOf` bounds).

r? @nikomatsakis or @oli-obk or @nagisa cc @sunfishcode

38 files changed, 175 insertions, 214 deletions

diff --git a/src/librustc/lint/context.rs b/src/librustc/lint/context.rs
index 7e2532bb1c4..5470aff77f8 100644
--- a/src/librustc/lint/context.rs
+++ b/src/librustc/lint/context.rs
@@ -783,11 +783,11 @@ impl<'a, 'tcx> LateContext<'a, 'tcx> {
     }
 }
 
-impl<'a, 'tcx> LayoutOf for &'a LateContext<'a, 'tcx> {
+impl<'a, 'tcx> LayoutOf for LateContext<'a, 'tcx> {
     type Ty = Ty<'tcx>;
     type TyLayout = Result<TyLayout<'tcx>, LayoutError<'tcx>>;
 
-    fn layout_of(self, ty: Ty<'tcx>) -> Self::TyLayout {
+    fn layout_of(&self, ty: Ty<'tcx>) -> Self::TyLayout {
         self.tcx.layout_of(self.param_env.and(ty))
     }
 }
diff --git a/src/librustc/middle/intrinsicck.rs b/src/librustc/middle/intrinsicck.rs
index 9d54e798469..0a5b1e184de 100644
--- a/src/librustc/middle/intrinsicck.rs
+++ b/src/librustc/middle/intrinsicck.rs
@@ -84,7 +84,7 @@ impl<'a, 'tcx> ExprVisitor<'a, 'tcx> {
             // `Option<typeof(function)>` to present a clearer error.
             let from = unpack_option_like(self.tcx.global_tcx(), from);
             if let (&ty::FnDef(..), SizeSkeleton::Known(size_to)) = (&from.sty, sk_to) {
-                if size_to == Pointer.size(self.tcx) {
+                if size_to == Pointer.size(&self.tcx) {
                     struct_span_err!(self.tcx.sess, span, E0591,
                                      "can't transmute zero-sized type")
                         .note(&format!("source type: {}", from))
diff --git a/src/librustc/mir/interpret/mod.rs b/src/librustc/mir/interpret/mod.rs
index 61b5886e783..f8a5dbc6905 100644
--- a/src/librustc/mir/interpret/mod.rs
+++ b/src/librustc/mir/interpret/mod.rs
@@ -86,18 +86,18 @@ pub trait PointerArithmetic: layout::HasDataLayout {
     // These are not supposed to be overridden.
 
     #[inline(always)]
-    fn pointer_size(self) -> Size {
+    fn pointer_size(&self) -> Size {
         self.data_layout().pointer_size
     }
 
     //// Trunace the given value to the pointer size; also return whether there was an overflow
-    fn truncate_to_ptr(self, val: u128) -> (u64, bool) {
+    fn truncate_to_ptr(&self, val: u128) -> (u64, bool) {
         let max_ptr_plus_1 = 1u128 << self.pointer_size().bits();
         ((val % max_ptr_plus_1) as u64, val >= max_ptr_plus_1)
     }
 
     // Overflow checking only works properly on the range from -u64 to +u64.
-    fn overflowing_signed_offset(self, val: u64, i: i128) -> (u64, bool) {
+    fn overflowing_signed_offset(&self, val: u64, i: i128) -> (u64, bool) {
         // FIXME: is it possible to over/underflow here?
         if i < 0 {
             // trickery to ensure that i64::min_value() works fine
@@ -109,23 +109,23 @@ pub trait PointerArithmetic: layout::HasDataLayout {
         }
     }
 
-    fn overflowing_offset(self, val: u64, i: u64) -> (u64, bool) {
+    fn overflowing_offset(&self, val: u64, i: u64) -> (u64, bool) {
         let (res, over1) = val.overflowing_add(i);
         let (res, over2) = self.truncate_to_ptr(res as u128);
         (res, over1 || over2)
     }
 
-    fn signed_offset<'tcx>(self, val: u64, i: i64) -> EvalResult<'tcx, u64> {
+    fn signed_offset<'tcx>(&self, val: u64, i: i64) -> EvalResult<'tcx, u64> {
         let (res, over) = self.overflowing_signed_offset(val, i as i128);
         if over { err!(Overflow(mir::BinOp::Add)) } else { Ok(res) }
     }
 
-    fn offset<'tcx>(self, val: u64, i: u64) -> EvalResult<'tcx, u64> {
+    fn offset<'tcx>(&self, val: u64, i: u64) -> EvalResult<'tcx, u64> {
         let (res, over) = self.overflowing_offset(val, i);
         if over { err!(Overflow(mir::BinOp::Add)) } else { Ok(res) }
     }
 
-    fn wrapping_signed_offset(self, val: u64, i: i64) -> u64 {
+    fn wrapping_signed_offset(&self, val: u64, i: i64) -> u64 {
         self.overflowing_signed_offset(val, i as i128).0
     }
 }
@@ -176,7 +176,7 @@ impl<'tcx, Tag> Pointer<Tag> {
         Pointer { alloc_id, offset, tag }
     }
 
-    pub fn wrapping_signed_offset(self, i: i64, cx: impl HasDataLayout) -> Self {
+    pub fn wrapping_signed_offset(self, i: i64, cx: &impl HasDataLayout) -> Self {
         Pointer::new_with_tag(
             self.alloc_id,
             Size::from_bytes(cx.data_layout().wrapping_signed_offset(self.offset.bytes(), i)),
@@ -184,12 +184,12 @@ impl<'tcx, Tag> Pointer<Tag> {
         )
     }
 
-    pub fn overflowing_signed_offset(self, i: i128, cx: impl HasDataLayout) -> (Self, bool) {
+    pub fn overflowing_signed_offset(self, i: i128, cx: &impl HasDataLayout) -> (Self, bool) {
         let (res, over) = cx.data_layout().overflowing_signed_offset(self.offset.bytes(), i);
         (Pointer::new_with_tag(self.alloc_id, Size::from_bytes(res), self.tag), over)
     }
 
-    pub fn signed_offset(self, i: i64, cx: impl HasDataLayout) -> EvalResult<'tcx, Self> {
+    pub fn signed_offset(self, i: i64, cx: &impl HasDataLayout) -> EvalResult<'tcx, Self> {
         Ok(Pointer::new_with_tag(
             self.alloc_id,
             Size::from_bytes(cx.data_layout().signed_offset(self.offset.bytes(), i)?),
@@ -197,12 +197,12 @@ impl<'tcx, Tag> Pointer<Tag> {
         ))
     }
 
-    pub fn overflowing_offset(self, i: Size, cx: impl HasDataLayout) -> (Self, bool) {
+    pub fn overflowing_offset(self, i: Size, cx: &impl HasDataLayout) -> (Self, bool) {
         let (res, over) = cx.data_layout().overflowing_offset(self.offset.bytes(), i.bytes());
         (Pointer::new_with_tag(self.alloc_id, Size::from_bytes(res), self.tag), over)
     }
 
-    pub fn offset(self, i: Size, cx: impl HasDataLayout) -> EvalResult<'tcx, Self> {
+    pub fn offset(self, i: Size, cx: &impl HasDataLayout) -> EvalResult<'tcx, Self> {
         Ok(Pointer::new_with_tag(
             self.alloc_id,
             Size::from_bytes(cx.data_layout().offset(self.offset.bytes(), i.bytes())?),
diff --git a/src/librustc/mir/interpret/value.rs b/src/librustc/mir/interpret/value.rs
index 4304f08a78f..3b8e19c6eca 100644
--- a/src/librustc/mir/interpret/value.rs
+++ b/src/librustc/mir/interpret/value.rs
@@ -65,7 +65,7 @@ impl<'tcx> ConstValue<'tcx> {
     pub fn new_slice(
         val: Scalar,
         len: u64,
-        cx: impl HasDataLayout
+        cx: &impl HasDataLayout
     ) -> Self {
         ConstValue::ScalarPair(val, Scalar::Bits {
             bits: len as u128,
@@ -121,7 +121,7 @@ impl<'tcx, Tag> Scalar<Tag> {
     }
 
     #[inline]
-    pub fn ptr_null(cx: impl HasDataLayout) -> Self {
+    pub fn ptr_null(cx: &impl HasDataLayout) -> Self {
         Scalar::Bits {
             bits: 0,
             size: cx.data_layout().pointer_size.bytes() as u8,
@@ -134,52 +134,52 @@ impl<'tcx, Tag> Scalar<Tag> {
     }
 
     #[inline]
-    pub fn ptr_signed_offset(self, i: i64, cx: impl HasDataLayout) -> EvalResult<'tcx, Self> {
-        let layout = cx.data_layout();
+    pub fn ptr_signed_offset(self, i: i64, cx: &impl HasDataLayout) -> EvalResult<'tcx, Self> {
+        let dl = cx.data_layout();
         match self {
             Scalar::Bits { bits, size } => {
-                assert_eq!(size as u64, layout.pointer_size.bytes());
+                assert_eq!(size as u64, dl.pointer_size.bytes());
                 Ok(Scalar::Bits {
-                    bits: layout.signed_offset(bits as u64, i)? as u128,
+                    bits: dl.signed_offset(bits as u64, i)? as u128,
                     size,
                 })
             }
-            Scalar::Ptr(ptr) => ptr.signed_offset(i, layout).map(Scalar::Ptr),
+            Scalar::Ptr(ptr) => ptr.signed_offset(i, dl).map(Scalar::Ptr),
         }
     }
 
     #[inline]
-    pub fn ptr_offset(self, i: Size, cx: impl HasDataLayout) -> EvalResult<'tcx, Self> {
-        let layout = cx.data_layout();
+    pub fn ptr_offset(self, i: Size, cx: &impl HasDataLayout) -> EvalResult<'tcx, Self> {
+        let dl = cx.data_layout();
         match self {
             Scalar::Bits { bits, size } => {
-                assert_eq!(size as u64, layout.pointer_size.bytes());
+                assert_eq!(size as u64, dl.pointer_size.bytes());
                 Ok(Scalar::Bits {
-                    bits: layout.offset(bits as u64, i.bytes())? as u128,
+                    bits: dl.offset(bits as u64, i.bytes())? as u128,
                     size,
                 })
             }
-            Scalar::Ptr(ptr) => ptr.offset(i, layout).map(Scalar::Ptr),
+            Scalar::Ptr(ptr) => ptr.offset(i, dl).map(Scalar::Ptr),
         }
     }
 
     #[inline]
-    pub fn ptr_wrapping_signed_offset(self, i: i64, cx: impl HasDataLayout) -> Self {
-        let layout = cx.data_layout();
+    pub fn ptr_wrapping_signed_offset(self, i: i64, cx: &impl HasDataLayout) -> Self {
+        let dl = cx.data_layout();
         match self {
             Scalar::Bits { bits, size } => {
-                assert_eq!(size as u64, layout.pointer_size.bytes());
+                assert_eq!(size as u64, dl.pointer_size.bytes());
                 Scalar::Bits {
-                    bits: layout.wrapping_signed_offset(bits as u64, i) as u128,
+                    bits: dl.wrapping_signed_offset(bits as u64, i) as u128,
                     size,
                 }
             }
-            Scalar::Ptr(ptr) => Scalar::Ptr(ptr.wrapping_signed_offset(i, layout)),
+            Scalar::Ptr(ptr) => Scalar::Ptr(ptr.wrapping_signed_offset(i, dl)),
         }
     }
 
     #[inline]
-    pub fn is_null_ptr(self, cx: impl HasDataLayout) -> bool {
+    pub fn is_null_ptr(self, cx: &impl HasDataLayout) -> bool {
         match self {
             Scalar::Bits { bits, size } => {
                 assert_eq!(size as u64, cx.data_layout().pointer_size.bytes());
@@ -301,7 +301,7 @@ impl<'tcx, Tag> Scalar<Tag> {
         Ok(b as u64)
     }
 
-    pub fn to_usize(self, cx: impl HasDataLayout) -> EvalResult<'static, u64> {
+    pub fn to_usize(self, cx: &impl HasDataLayout) -> EvalResult<'static, u64> {
         let b = self.to_bits(cx.data_layout().pointer_size)?;
         assert_eq!(b as u64 as u128, b);
         Ok(b as u64)
@@ -331,7 +331,7 @@ impl<'tcx, Tag> Scalar<Tag> {
         Ok(b as i64)
     }
 
-    pub fn to_isize(self, cx: impl HasDataLayout) -> EvalResult<'static, i64> {
+    pub fn to_isize(self, cx: &impl HasDataLayout) -> EvalResult<'static, i64> {
         let b = self.to_bits(cx.data_layout().pointer_size)?;
         let b = sign_extend(b, cx.data_layout().pointer_size) as i128;
         assert_eq!(b as i64 as i128, b);
diff --git a/src/librustc/traits/error_reporting.rs b/src/librustc/traits/error_reporting.rs
index e6ae0557c33..fbada789956 100644
--- a/src/librustc/traits/error_reporting.rs
+++ b/src/librustc/traits/error_reporting.rs
@@ -428,7 +428,7 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> {
                 ));
                 let tcx = self.tcx;
                 if let Some(len) = len.val.try_to_scalar().and_then(|scalar| {
-                    scalar.to_usize(tcx).ok()
+                    scalar.to_usize(&tcx).ok()
                 }) {
                     flags.push((
                         "_Self".to_owned(),
diff --git a/src/librustc/ty/layout.rs b/src/librustc/ty/layout.rs
index 55005721617..5aeba652f32 100644
--- a/src/librustc/ty/layout.rs
+++ b/src/librustc/ty/layout.rs
@@ -30,7 +30,7 @@ pub use rustc_target::abi::*;
 
 pub trait IntegerExt {
     fn to_ty<'a, 'tcx>(&self, tcx: TyCtxt<'a, 'tcx, 'tcx>, signed: bool) -> Ty<'tcx>;
-    fn from_attr<C: HasDataLayout>(cx: C, ity: attr::IntType) -> Integer;
+    fn from_attr<C: HasDataLayout>(cx: &C, ity: attr::IntType) -> Integer;
     fn repr_discr<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
                             ty: Ty<'tcx>,
                             repr: &ReprOptions,
@@ -56,7 +56,7 @@ impl IntegerExt for Integer {
     }
 
     /// Get the Integer type from an attr::IntType.
-    fn from_attr<C: HasDataLayout>(cx: C, ity: attr::IntType) -> Integer {
+    fn from_attr<C: HasDataLayout>(cx: &C, ity: attr::IntType) -> Integer {
         let dl = cx.data_layout();
 
         match ity {
@@ -92,7 +92,7 @@ impl IntegerExt for Integer {
         let min_default = I8;
 
         if let Some(ity) = repr.int {
-            let discr = Integer::from_attr(tcx, ity);
+            let discr = Integer::from_attr(&tcx, ity);
             let fit = if ity.is_signed() { signed_fit } else { unsigned_fit };
             if discr < fit {
                 bug!("Integer::repr_discr: `#[repr]` hint too small for \
@@ -202,14 +202,13 @@ pub fn provide(providers: &mut ty::query::Providers<'_>) {
     };
 }
 
-#[derive(Copy, Clone)]
 pub struct LayoutCx<'tcx, C> {
     pub tcx: C,
     pub param_env: ty::ParamEnv<'tcx>
 }
 
 impl<'a, 'tcx> LayoutCx<'tcx, TyCtxt<'a, 'tcx, 'tcx>> {
-    fn layout_raw_uncached(self, ty: Ty<'tcx>)
+    fn layout_raw_uncached(&self, ty: Ty<'tcx>)
                            -> Result<&'tcx LayoutDetails, LayoutError<'tcx>> {
         let tcx = self.tcx;
         let param_env = self.param_env;
@@ -899,7 +898,7 @@ impl<'a, 'tcx> LayoutCx<'tcx, TyCtxt<'a, 'tcx, 'tcx>> {
 
                 let (mut min, mut max) = (i128::max_value(), i128::min_value());
                 let discr_type = def.repr.discr_type();
-                let bits = Integer::from_attr(tcx, discr_type).size().bits();
+                let bits = Integer::from_attr(self, discr_type).size().bits();
                 for (i, discr) in def.discriminants(tcx).enumerate() {
                     if variants[i].iter().any(|f| f.abi.is_uninhabited()) {
                         continue;
@@ -1141,7 +1140,7 @@ impl<'a, 'tcx> LayoutCx<'tcx, TyCtxt<'a, 'tcx, 'tcx>> {
     /// This is invoked by the `layout_raw` query to record the final
     /// layout of each type.
     #[inline]
-    fn record_layout_for_printing(self, layout: TyLayout<'tcx>) {
+    fn record_layout_for_printing(&self, layout: TyLayout<'tcx>) {
         // If we are running with `-Zprint-type-sizes`, record layouts for
         // dumping later. Ignore layouts that are done with non-empty
         // environments or non-monomorphic layouts, as the user only wants
@@ -1158,7 +1157,7 @@ impl<'a, 'tcx> LayoutCx<'tcx, TyCtxt<'a, 'tcx, 'tcx>> {
         self.record_layout_for_printing_outlined(layout)
     }
 
-    fn record_layout_for_printing_outlined(self, layout: TyLayout<'tcx>) {
+    fn record_layout_for_printing_outlined(&self, layout: TyLayout<'tcx>) {
         // (delay format until we actually need it)
         let record = |kind, packed, opt_discr_size, variants| {
             let type_desc = format!("{:?}", layout.ty);
@@ -1478,7 +1477,7 @@ impl<'a, 'tcx> LayoutOf for LayoutCx<'tcx, TyCtxt<'a, 'tcx, 'tcx>> {
 
     /// Computes the layout of a type. Note that this implicitly
     /// executes in "reveal all" mode.
-    fn layout_of(self, ty: Ty<'tcx>) -> Self::TyLayout {
+    fn layout_of(&self, ty: Ty<'tcx>) -> Self::TyLayout {
         let param_env = self.param_env.with_reveal_all();
         let ty = self.tcx.normalize_erasing_regions(param_env, ty);
         let details = self.tcx.layout_raw(param_env.and(ty))?;
@@ -1505,7 +1504,7 @@ impl<'a, 'tcx> LayoutOf for LayoutCx<'tcx, ty::query::TyCtxtAt<'a, 'tcx, 'tcx>>
 
     /// Computes the layout of a type. Note that this implicitly
     /// executes in "reveal all" mode.
-    fn layout_of(self, ty: Ty<'tcx>) -> Self::TyLayout {
+    fn layout_of(&self, ty: Ty<'tcx>) -> Self::TyLayout {
         let param_env = self.param_env.with_reveal_all();
         let ty = self.tcx.normalize_erasing_regions(param_env, ty);
         let details = self.tcx.layout_raw(param_env.and(ty))?;
@@ -1563,7 +1562,7 @@ impl<'a, 'tcx, C> TyLayoutMethods<'tcx, C> for Ty<'tcx>
     where C: LayoutOf<Ty = Ty<'tcx>> + HasTyCtxt<'tcx>,
           C::TyLayout: MaybeResult<TyLayout<'tcx>>
 {
-    fn for_variant(this: TyLayout<'tcx>, cx: C, variant_index: usize) -> TyLayout<'tcx> {
+    fn for_variant(this: TyLayout<'tcx>, cx: &C, variant_index: usize) -> TyLayout<'tcx> {
         let details = match this.variants {
             Variants::Single { index } if index == variant_index => this.details,
 
@@ -1602,7 +1601,7 @@ impl<'a, 'tcx, C> TyLayoutMethods<'tcx, C> for Ty<'tcx>
         }
     }
 
-    fn field(this: TyLayout<'tcx>, cx: C, i: usize) -> C::TyLayout {
+    fn field(this: TyLayout<'tcx>, cx: &C, i: usize) -> C::TyLayout {
         let tcx = cx.tcx();
         cx.layout_of(match this.ty.sty {
             ty::Bool |
@@ -1699,7 +1698,7 @@ impl<'a, 'tcx, C> TyLayoutMethods<'tcx, C> for Ty<'tcx>
                     Variants::Tagged { tag: ref discr, .. } |
                     Variants::NicheFilling { niche: ref discr, .. } => {
                         assert_eq!(i, 0);
-                        let layout = LayoutDetails::scalar(tcx, discr.clone());
+                        let layout = LayoutDetails::scalar(cx, discr.clone());
                         return MaybeResult::from_ok(TyLayout {
                             details: tcx.intern_layout(layout),
                             ty: discr.value.to_ty(tcx)
@@ -1725,7 +1724,7 @@ struct Niche {
 impl Niche {
     fn reserve<'a, 'tcx>(
         &self,
-        cx: LayoutCx<'tcx, TyCtxt<'a, 'tcx, 'tcx>>,
+        cx: &LayoutCx<'tcx, TyCtxt<'a, 'tcx, 'tcx>>,
         count: u128,
     ) -> Option<(u128, Scalar)> {
         if count > self.available {
@@ -1745,7 +1744,7 @@ impl<'a, 'tcx> LayoutCx<'tcx, TyCtxt<'a, 'tcx, 'tcx>> {
     /// Find the offset of a niche leaf field, starting from
     /// the given type and recursing through aggregates.
     // FIXME(eddyb) traverse already optimized enums.
-    fn find_niche(self, layout: TyLayout<'tcx>) -> Result<Option<Niche>, LayoutError<'tcx>> {
+    fn find_niche(&self, layout: TyLayout<'tcx>) -> Result<Option<Niche>, LayoutError<'tcx>> {
         let scalar_niche = |scalar: &Scalar, offset| {
             let Scalar { value, valid_range: ref v } = *scalar;
 
diff --git a/src/librustc/ty/util.rs b/src/librustc/ty/util.rs
index 9ba5bf9add1..3d0c54d6b0a 100644
--- a/src/librustc/ty/util.rs
+++ b/src/librustc/ty/util.rs
@@ -43,7 +43,7 @@ impl<'tcx> fmt::Display for Discr<'tcx> {
         match self.ty.sty {
             ty::Int(ity) => {
                 let bits = ty::tls::with(|tcx| {
-                    Integer::from_attr(tcx, SignedInt(ity)).size().bits()
+                    Integer::from_attr(&tcx, SignedInt(ity)).size().bits()
                 });
                 let x = self.val as i128;
                 // sign extend the raw representation to be an i128
@@ -62,8 +62,8 @@ impl<'tcx> Discr<'tcx> {
     }
     pub fn checked_add<'a, 'gcx>(self, tcx: TyCtxt<'a, 'gcx, 'tcx>, n: u128) -> (Self, bool) {
         let (int, signed) = match self.ty.sty {
-            Int(ity) => (Integer::from_attr(tcx, SignedInt(ity)), true),
-            Uint(uty) => (Integer::from_attr(tcx, UnsignedInt(uty)), false),
+            Int(ity) => (Integer::from_attr(&tcx, SignedInt(ity)), true),
+            Uint(uty) => (Integer::from_attr(&tcx, UnsignedInt(uty)), false),
             _ => bug!("non integer discriminant"),
         };
 
diff --git a/src/librustc_codegen_llvm/context.rs b/src/librustc_codegen_llvm/context.rs
index 241f7989e16..120449ae2af 100644
--- a/src/librustc_codegen_llvm/context.rs
+++ b/src/librustc_codegen_llvm/context.rs
@@ -446,29 +446,29 @@ impl<'b, 'tcx> CodegenCx<'b, 'tcx> {
     }
 }
 
-impl ty::layout::HasDataLayout for &'a CodegenCx<'ll, 'tcx> {
+impl ty::layout::HasDataLayout for CodegenCx<'ll, 'tcx> {
     fn data_layout(&self) -> &ty::layout::TargetDataLayout {
         &self.tcx.data_layout
     }
 }
 
-impl HasTargetSpec for &'a CodegenCx<'ll, 'tcx> {
+impl HasTargetSpec for CodegenCx<'ll, 'tcx> {
     fn target_spec(&self) -> &Target {
         &self.tcx.sess.target.target
     }
 }
 
-impl ty::layout::HasTyCtxt<'tcx> for &'a CodegenCx<'ll, 'tcx> {
-    fn tcx<'b>(&'b self) -> TyCtxt<'b, 'tcx, 'tcx> {
+impl ty::layout::HasTyCtxt<'tcx> for CodegenCx<'ll, 'tcx> {
+    fn tcx<'a>(&'a self) -> TyCtxt<'a, 'tcx, 'tcx> {
         self.tcx
     }
 }
 
-impl LayoutOf for &'a CodegenCx<'ll, 'tcx> {
+impl LayoutOf for CodegenCx<'ll, 'tcx> {
     type Ty = Ty<'tcx>;
     type TyLayout = TyLayout<'tcx>;
 
-    fn layout_of(self, ty: Ty<'tcx>) -> Self::TyLayout {
+    fn layout_of(&self, ty: Ty<'tcx>) -> Self::TyLayout {
         self.tcx.layout_of(ty::ParamEnv::reveal_all().and(ty))
             .unwrap_or_else(|e| if let LayoutError::SizeOverflow(_) = e {
                 self.sess().fatal(&e.to_string())
diff --git a/src/librustc_codegen_llvm/mir/constant.rs b/src/librustc_codegen_llvm/mir/constant.rs
index 1f66ee36170..586a4907740 100644
--- a/src/librustc_codegen_llvm/mir/constant.rs
+++ b/src/librustc_codegen_llvm/mir/constant.rs
@@ -87,8 +87,8 @@ pub fn scalar_to_llvm(
 
 pub fn const_alloc_to_llvm(cx: &CodegenCx<'ll, '_>, alloc: &Allocation) -> &'ll Value {
     let mut llvals = Vec::with_capacity(alloc.relocations.len() + 1);
-    let layout = cx.data_layout();
-    let pointer_size = layout.pointer_size.bytes() as usize;
+    let dl = cx.data_layout();
+    let pointer_size = dl.pointer_size.bytes() as usize;
 
     let mut next_offset = 0;
     for &(offset, ((), alloc_id)) in alloc.relocations.iter() {
@@ -99,7 +99,7 @@ pub fn const_alloc_to_llvm(cx: &CodegenCx<'ll, '_>, alloc: &Allocation) -> &'ll
             llvals.push(C_bytes(cx, &alloc.bytes[next_offset..offset]));
         }
         let ptr_offset = read_target_uint(
-            layout.endian,
+            dl.endian,
             &alloc.bytes[offset..(offset + pointer_size)],
         ).expect("const_alloc_to_llvm: could not read relocation pointer") as u64;
         llvals.push(scalar_to_llvm(
diff --git a/src/librustc_lint/types.rs b/src/librustc_lint/types.rs
index 2e19b441d0e..0b788a8fd97 100644
--- a/src/librustc_lint/types.rs
+++ b/src/librustc_lint/types.rs
@@ -377,13 +377,13 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for TypeLimits {
             let (t, actually) = match ty {
                 ty::Int(t) => {
                     let ity = attr::IntType::SignedInt(t);
-                    let bits = layout::Integer::from_attr(cx.tcx, ity).size().bits();
+                    let bits = layout::Integer::from_attr(&cx.tcx, ity).size().bits();
                     let actually = (val << (128 - bits)) as i128 >> (128 - bits);
                     (format!("{:?}", t), actually.to_string())
                 }
                 ty::Uint(t) => {
                     let ity = attr::IntType::UnsignedInt(t);
-                    let bits = layout::Integer::from_attr(cx.tcx, ity).size().bits();
+                    let bits = layout::Integer::from_attr(&cx.tcx, ity).size().bits();
                     let actually = (val << (128 - bits)) >> (128 - bits);
                     (format!("{:?}", t), actually.to_string())
                 }
@@ -829,7 +829,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for VariantSizeDifferences {
                 Ok(layout) => {
                     let variants = &layout.variants;
                     if let layout::Variants::Tagged { ref variants, ref tag, .. } = variants {
-                        let discr_size = tag.value.size(cx.tcx).bytes();
+                        let discr_size = tag.value.size(&cx.tcx).bytes();
 
                         debug!("enum `{}` is {} bytes large with layout:\n{:#?}",
                                t, layout.size.bytes(), layout);
diff --git a/src/librustc_mir/hair/cx/mod.rs b/src/librustc_mir/hair/cx/mod.rs
index 5f798135966..3a56d261111 100644
--- a/src/librustc_mir/hair/cx/mod.rs
+++ b/src/librustc_mir/hair/cx/mod.rs
@@ -165,7 +165,7 @@ impl<'a, 'gcx, 'tcx> Cx<'a, 'gcx, 'tcx> {
             LitKind::Str(ref s, _) => {
                 let s = s.as_str();
                 let id = self.tcx.allocate_bytes(s.as_bytes());
-                ConstValue::new_slice(Scalar::Ptr(id.into()), s.len() as u64, self.tcx)
+                ConstValue::new_slice(Scalar::Ptr(id.into()), s.len() as u64, &self.tcx)
             },
             LitKind::ByteStr(ref data) => {
                 let id = self.tcx.allocate_bytes(data);
diff --git a/src/librustc_mir/hair/pattern/_match.rs b/src/librustc_mir/hair/pattern/_match.rs
index d53bb1dc4d6..69ca21c5624 100644
--- a/src/librustc_mir/hair/pattern/_match.rs
+++ b/src/librustc_mir/hair/pattern/_match.rs
@@ -669,14 +669,14 @@ fn all_constructors<'a, 'tcx: 'a>(cx: &mut MatchCheckCtxt<'a, 'tcx>,
         }
         ty::Int(ity) if exhaustive_integer_patterns => {
             // FIXME(49937): refactor these bit manipulations into interpret.
-            let bits = Integer::from_attr(cx.tcx, SignedInt(ity)).size().bits() as u128;
+            let bits = Integer::from_attr(&cx.tcx, SignedInt(ity)).size().bits() as u128;
             let min = 1u128 << (bits - 1);
             let max = (1u128 << (bits - 1)) - 1;
             vec![ConstantRange(min, max, pcx.ty, RangeEnd::Included)]
         }
         ty::Uint(uty) if exhaustive_integer_patterns => {
             // FIXME(49937): refactor these bit manipulations into interpret.
-            let bits = Integer::from_attr(cx.tcx, UnsignedInt(uty)).size().bits() as u128;
+            let bits = Integer::from_attr(&cx.tcx, UnsignedInt(uty)).size().bits() as u128;
             let max = !0u128 >> (128 - bits);
             vec![ConstantRange(0, max, pcx.ty, RangeEnd::Included)]
         }
@@ -862,7 +862,7 @@ impl<'tcx> IntRange<'tcx> {
     fn signed_bias(tcx: TyCtxt<'_, 'tcx, 'tcx>, ty: Ty<'tcx>) -> u128 {
         match ty.sty {
             ty::Int(ity) => {
-                let bits = Integer::from_attr(tcx, SignedInt(ity)).size().bits() as u128;
+                let bits = Integer::from_attr(&tcx, SignedInt(ity)).size().bits() as u128;
                 1u128 << (bits - 1)
             }
             _ => 0
diff --git a/src/librustc_mir/hair/pattern/mod.rs b/src/librustc_mir/hair/pattern/mod.rs
index bff87da9c77..0e1f8d1d328 100644
--- a/src/librustc_mir/hair/pattern/mod.rs
+++ b/src/librustc_mir/hair/pattern/mod.rs
@@ -1313,7 +1313,7 @@ fn lit_to_const<'a, 'tcx>(lit: &'tcx ast::LitKind,
         LitKind::Str(ref s, _) => {
             let s = s.as_str();
             let id = tcx.allocate_bytes(s.as_bytes());
-            ConstValue::new_slice(Scalar::Ptr(id.into()), s.len() as u64, tcx)
+            ConstValue::new_slice(Scalar::Ptr(id.into()), s.len() as u64, &tcx)
         },
         LitKind::ByteStr(ref data) => {
             let id = tcx.allocate_bytes(data);
diff --git a/src/librustc_mir/interpret/cast.rs b/src/librustc_mir/interpret/cast.rs
index 01dd995bbee..06748d60e45 100644
--- a/src/librustc_mir/interpret/cast.rs
+++ b/src/librustc_mir/interpret/cast.rs
@@ -331,7 +331,7 @@ impl<'a, 'mir, 'tcx, M: Machine<'a, 'mir, 'tcx>> EvalContext<'a, 'mir, 'tcx, M>
                 let val = Immediate::new_slice(
                     ptr,
                     length.unwrap_usize(self.tcx.tcx),
-                    self.tcx.tcx,
+                    self,
                 );
                 self.write_immediate(val, dest)
             }
@@ -394,7 +394,7 @@ impl<'a, 'mir, 'tcx, M: Machine<'a, 'mir, 'tcx>> EvalContext<'a, 'mir, 'tcx, M>
                             src_field.into()
                         }
                         Err(..) => {
-                            let src_field_layout = src.layout.field(&self, i)?;
+                            let src_field_layout = src.layout.field(self, i)?;
                             // this must be a field covering the entire thing
                             assert_eq!(src.layout.fields.offset(i).bytes(), 0);
                             assert_eq!(src_field_layout.size, src.layout.size);
diff --git a/src/librustc_mir/interpret/eval_context.rs b/src/librustc_mir/interpret/eval_context.rs
index 8cb3f9d4d74..fc13c5fef2d 100644
--- a/src/librustc_mir/interpret/eval_context.rs
+++ b/src/librustc_mir/interpret/eval_context.rs
@@ -139,8 +139,8 @@ impl<'tcx, Tag> LocalValue<Tag> {
     }
 }
 
-impl<'b, 'a, 'mir, 'tcx, M: Machine<'a, 'mir, 'tcx>> HasDataLayout
-    for &'b EvalContext<'a, 'mir, 'tcx, M>
+impl<'a, 'mir, 'tcx, M: Machine<'a, 'mir, 'tcx>> HasDataLayout
+    for EvalContext<'a, 'mir, 'tcx, M>
 {
     #[inline]
     fn data_layout(&self) -> &layout::TargetDataLayout {
@@ -148,16 +148,7 @@ impl<'b, 'a, 'mir, 'tcx, M: Machine<'a, 'mir, 'tcx>> HasDataLayout
     }
 }
 
-impl<'c, 'b, 'a, 'mir, 'tcx, M: Machine<'a, 'mir, 'tcx>> HasDataLayout
-    for &'c &'b mut EvalContext<'a, 'mir, 'tcx, M>
-{
-    #[inline]
-    fn data_layout(&self) -> &layout::TargetDataLayout {
-        &self.tcx.data_layout
-    }
-}
-
-impl<'b, 'a, 'mir, 'tcx, M> layout::HasTyCtxt<'tcx> for &'b EvalContext<'a, 'mir, 'tcx, M>
+impl<'a, 'mir, 'tcx, M> layout::HasTyCtxt<'tcx> for EvalContext<'a, 'mir, 'tcx, M>
     where M: Machine<'a, 'mir, 'tcx>
 {
     #[inline]
@@ -166,40 +157,19 @@ impl<'b, 'a, 'mir, 'tcx, M> layout::HasTyCtxt<'tcx> for &'b EvalContext<'a, 'mir
     }
 }
 
-impl<'c, 'b, 'a, 'mir, 'tcx, M: Machine<'a, 'mir, 'tcx>> layout::HasTyCtxt<'tcx>
-    for &'c &'b mut EvalContext<'a, 'mir, 'tcx, M>
-{
-    #[inline]
-    fn tcx<'d>(&'d self) -> TyCtxt<'d, 'tcx, 'tcx> {
-        *self.tcx
-    }
-}
-
-impl<'b, 'a, 'mir, 'tcx, M: Machine<'a, 'mir, 'tcx>> LayoutOf
-    for &'b EvalContext<'a, 'mir, 'tcx, M>
+impl<'a, 'mir, 'tcx, M: Machine<'a, 'mir, 'tcx>> LayoutOf
+    for EvalContext<'a, 'mir, 'tcx, M>
 {
     type Ty = Ty<'tcx>;
     type TyLayout = EvalResult<'tcx, TyLayout<'tcx>>;
 
     #[inline]
-    fn layout_of(self, ty: Ty<'tcx>) -> Self::TyLayout {
+    fn layout_of(&self, ty: Ty<'tcx>) -> Self::TyLayout {
         self.tcx.layout_of(self.param_env.and(ty))
             .map_err(|layout| EvalErrorKind::Layout(layout).into())
     }
 }
 
-impl<'c, 'b, 'a, 'mir, 'tcx, M: Machine<'a, 'mir, 'tcx>> LayoutOf
-    for &'c &'b mut EvalContext<'a, 'mir, 'tcx, M>
-{
-    type Ty = Ty<'tcx>;
-    type TyLayout = EvalResult<'tcx, TyLayout<'tcx>>;
-
-    #[inline]
-    fn layout_of(self, ty: Ty<'tcx>) -> Self::TyLayout {
-        (&**self).layout_of(ty)
-    }
-}
-
 impl<'a, 'mir, 'tcx: 'mir, M: Machine<'a, 'mir, 'tcx>> EvalContext<'a, 'mir, 'tcx, M> {
     pub fn new(
         tcx: TyCtxtAt<'a, 'tcx, 'tcx>,
@@ -335,7 +305,7 @@ impl<'a, 'mir, 'tcx: 'mir, M: Machine<'a, 'mir, 'tcx>> EvalContext<'a, 'mir, 'tc
 
     pub fn str_to_immediate(&mut self, s: &str) -> EvalResult<'tcx, Immediate<M::PointerTag>> {
         let ptr = self.memory.allocate_static_bytes(s.as_bytes()).with_default_tag();
-        Ok(Immediate::new_slice(Scalar::Ptr(ptr), s.len() as u64, self.tcx.tcx))
+        Ok(Immediate::new_slice(Scalar::Ptr(ptr), s.len() as u64, self))
     }
 
     /// Return the actual dynamic size and alignment of the place at the given type.
diff --git a/src/librustc_mir/interpret/memory.rs b/src/librustc_mir/interpret/memory.rs
index a9ef35845fc..a0231f3feb1 100644
--- a/src/librustc_mir/interpret/memory.rs
+++ b/src/librustc_mir/interpret/memory.rs
@@ -77,16 +77,8 @@ pub struct Memory<'a, 'mir, 'tcx: 'a + 'mir, M: Machine<'a, 'mir, 'tcx>> {
     pub(super) tcx: TyCtxtAt<'a, 'tcx, 'tcx>,
 }
 
-impl<'b, 'a, 'mir, 'tcx, M: Machine<'a, 'mir, 'tcx>> HasDataLayout
-    for &'b Memory<'a, 'mir, 'tcx, M>
-{
-    #[inline]
-    fn data_layout(&self) -> &TargetDataLayout {
-        &self.tcx.data_layout
-    }
-}
-impl<'a, 'b, 'c, 'mir, 'tcx, M: Machine<'a, 'mir, 'tcx>> HasDataLayout
-    for &'b &'c mut Memory<'a, 'mir, 'tcx, M>
+impl<'a, 'mir, 'tcx, M: Machine<'a, 'mir, 'tcx>> HasDataLayout
+    for Memory<'a, 'mir, 'tcx, M>
 {
     #[inline]
     fn data_layout(&self) -> &TargetDataLayout {
diff --git a/src/librustc_mir/interpret/operand.rs b/src/librustc_mir/interpret/operand.rs
index 0da03009448..6f66dd1e70a 100644
--- a/src/librustc_mir/interpret/operand.rs
+++ b/src/librustc_mir/interpret/operand.rs
@@ -112,7 +112,7 @@ impl<'tcx, Tag> ScalarMaybeUndef<Tag> {
     }
 
     #[inline(always)]
-    pub fn to_usize(self, cx: impl HasDataLayout) -> EvalResult<'tcx, u64> {
+    pub fn to_usize(self, cx: &impl HasDataLayout) -> EvalResult<'tcx, u64> {
         self.not_undef()?.to_usize(cx)
     }
 
@@ -132,7 +132,7 @@ impl<'tcx, Tag> ScalarMaybeUndef<Tag> {
     }
 
     #[inline(always)]
-    pub fn to_isize(self, cx: impl HasDataLayout) -> EvalResult<'tcx, i64> {
+    pub fn to_isize(self, cx: &impl HasDataLayout) -> EvalResult<'tcx, i64> {
         self.not_undef()?.to_isize(cx)
     }
 }
@@ -178,7 +178,7 @@ impl<'tcx, Tag> Immediate<Tag> {
     pub fn new_slice(
         val: Scalar<Tag>,
         len: u64,
-        cx: impl HasDataLayout
+        cx: &impl HasDataLayout
     ) -> Self {
         Immediate::ScalarPair(
             val.into(),
@@ -743,7 +743,7 @@ impl<'a, 'mir, 'tcx, M: Machine<'a, 'mir, 'tcx>> EvalContext<'a, 'mir, 'tcx, M>
                         .ty_adt_def().expect("tagged layout corresponds to adt")
                         .repr
                         .discr_type();
-                    let discr_ty = layout::Integer::from_attr(self.tcx.tcx, discr_ty);
+                    let discr_ty = layout::Integer::from_attr(self, discr_ty);
                     let shift = 128 - discr_ty.size().bits();
                     let truncatee = sexted as u128;
                     (truncatee << shift) >> shift
diff --git a/src/librustc_mir/interpret/place.rs b/src/librustc_mir/interpret/place.rs
index 58e4e3ce96b..fa4d31846df 100644
--- a/src/librustc_mir/interpret/place.rs
+++ b/src/librustc_mir/interpret/place.rs
@@ -128,7 +128,7 @@ impl<Tag> MemPlace<Tag> {
 
     /// Produces a Place that will error if attempted to be read from or written to
     #[inline(always)]
-    pub fn null(cx: impl HasDataLayout) -> Self {
+    pub fn null(cx: &impl HasDataLayout) -> Self {
         Self::from_scalar_ptr(Scalar::ptr_null(cx), Align::from_bytes(1, 1).unwrap())
     }
 
@@ -156,7 +156,7 @@ impl<Tag> MemPlace<Tag> {
 impl<'tcx, Tag> MPlaceTy<'tcx, Tag> {
     /// Produces a MemPlace that works for ZST but nothing else
     #[inline]
-    pub fn dangling(layout: TyLayout<'tcx>, cx: impl HasDataLayout) -> Self {
+    pub fn dangling(layout: TyLayout<'tcx>, cx: &impl HasDataLayout) -> Self {
         MPlaceTy {
             mplace: MemPlace::from_scalar_ptr(
                 Scalar::from_uint(layout.align.abi(), cx.pointer_size()),
@@ -172,7 +172,7 @@ impl<'tcx, Tag> MPlaceTy<'tcx, Tag> {
     }
 
     #[inline]
-    pub(super) fn len(self, cx: impl HasDataLayout) -> EvalResult<'tcx, u64> {
+    pub(super) fn len(self, cx: &impl HasDataLayout) -> EvalResult<'tcx, u64> {
         if self.layout.is_unsized() {
             // We need to consult `meta` metadata
             match self.layout.ty.sty {
@@ -217,7 +217,7 @@ impl<'tcx, Tag: ::std::fmt::Debug> OpTy<'tcx, Tag> {
 impl<'tcx, Tag: ::std::fmt::Debug> Place<Tag> {
     /// Produces a Place that will error if attempted to be read from or written to
     #[inline(always)]
-    pub fn null(cx: impl HasDataLayout) -> Self {
+    pub fn null(cx: &impl HasDataLayout) -> Self {
         Place::Ptr(MemPlace::null(cx))
     }
 
@@ -510,7 +510,7 @@ where
             Place::Ptr(mplace) =>
                 self.mplace_downcast(MPlaceTy { mplace, layout: base.layout }, variant)?.into(),
             Place::Local { .. } => {
-                let layout = base.layout.for_variant(&self, variant);
+                let layout = base.layout.for_variant(self, variant);
                 PlaceTy { layout, ..base }
             }
         })
@@ -738,10 +738,10 @@ where
                     _ => bug!("write_immediate_to_mplace: invalid ScalarPair layout: {:#?}",
                               dest.layout)
                 };
-                let (a_size, b_size) = (a.size(&self), b.size(&self));
-                let (a_align, b_align) = (a.align(&self), b.align(&self));
+                let (a_size, b_size) = (a.size(self), b.size(self));
+                let (a_align, b_align) = (a.align(self), b.align(self));
                 let b_offset = a_size.abi_align(b_align);
-                let b_ptr = ptr.offset(b_offset, &self)?.into();
+                let b_ptr = ptr.offset(b_offset, self)?.into();
 
                 // It is tempting to verify `b_offset` against `layout.fields.offset(1)`,
                 // but that does not work: We could be a newtype around a pair, then the
@@ -896,7 +896,7 @@ where
         if layout.is_unsized() {
             assert!(self.tcx.features().unsized_locals, "cannot alloc memory for unsized type");
             // FIXME: What should we do here? We should definitely also tag!
-            Ok(MPlaceTy::dangling(layout, &self))
+            Ok(MPlaceTy::dangling(layout, self))
         } else {
             let ptr = self.memory.allocate(layout.size, layout.align, kind)?;
             let ptr = M::tag_new_allocation(self, ptr, kind)?;
@@ -923,7 +923,7 @@ where
                 // raw discriminants for enums are isize or bigger during
                 // their computation, but the in-memory tag is the smallest possible
                 // representation
-                let size = tag.value.size(self.tcx.tcx);
+                let size = tag.value.size(self);
                 let shift = 128 - size.bits();
                 let discr_val = (discr_val << shift) >> shift;
 
diff --git a/src/librustc_mir/interpret/step.rs b/src/librustc_mir/interpret/step.rs
index ea8fcfe260b..db055204c0a 100644
--- a/src/librustc_mir/interpret/step.rs
+++ b/src/librustc_mir/interpret/step.rs
@@ -217,7 +217,7 @@ impl<'a, 'mir, 'tcx, M: Machine<'a, 'mir, 'tcx>> EvalContext<'a, 'mir, 'tcx, M>
             Repeat(ref operand, _) => {
                 let op = self.eval_operand(operand, None)?;
                 let dest = self.force_allocation(dest)?;
-                let length = dest.len(&self)?;
+                let length = dest.len(self)?;
 
                 if length > 0 {
                     // write the first
@@ -227,7 +227,7 @@ impl<'a, 'mir, 'tcx, M: Machine<'a, 'mir, 'tcx>> EvalContext<'a, 'mir, 'tcx, M>
                     if length > 1 {
                         // copy the rest
                         let (dest, dest_align) = first.to_scalar_ptr_align();
-                        let rest = dest.ptr_offset(first.layout.size, &self)?;
+                        let rest = dest.ptr_offset(first.layout.size, self)?;
                         self.memory.copy_repeatedly(
                             dest, dest_align, rest, dest_align, first.layout.size, length - 1, true
                         )?;
@@ -239,7 +239,7 @@ impl<'a, 'mir, 'tcx, M: Machine<'a, 'mir, 'tcx>> EvalContext<'a, 'mir, 'tcx, M>
                 // FIXME(CTFE): don't allow computing the length of arrays in const eval
                 let src = self.eval_place(place)?;
                 let mplace = self.force_allocation(src)?;
-                let len = mplace.len(&self)?;
+                let len = mplace.len(self)?;
                 let size = self.pointer_size();
                 self.write_scalar(
                     Scalar::from_uint(len, size),
diff --git a/src/librustc_mir/interpret/terminator.rs b/src/librustc_mir/interpret/terminator.rs
index 44262aeae02..b5df625b302 100644
--- a/src/librustc_mir/interpret/terminator.rs
+++ b/src/librustc_mir/interpret/terminator.rs
@@ -405,7 +405,7 @@ impl<'a, 'mir, 'tcx, M: Machine<'a, 'mir, 'tcx>> EvalContext<'a, 'mir, 'tcx, M>
                 let ptr = self.ref_to_mplace(self.read_immediate(args[0])?)?;
                 let vtable = ptr.vtable()?;
                 let fn_ptr = self.memory.read_ptr_sized(
-                    vtable.offset(ptr_size * (idx as u64 + 3), &self)?,
+                    vtable.offset(ptr_size * (idx as u64 + 3), self)?,
                     ptr_align
                 )?.to_ptr()?;
                 let instance = self.memory.get_fn(fn_ptr)?;
@@ -416,7 +416,7 @@ impl<'a, 'mir, 'tcx, M: Machine<'a, 'mir, 'tcx>> EvalContext<'a, 'mir, 'tcx, M>
                 let mut args = args.to_vec();
                 let pointee = args[0].layout.ty.builtin_deref(true).unwrap().ty;
                 let fake_fat_ptr_ty = self.tcx.mk_mut_ptr(pointee);
-                args[0].layout = self.layout_of(fake_fat_ptr_ty)?.field(&self, 0)?;
+                args[0].layout = self.layout_of(fake_fat_ptr_ty)?.field(self, 0)?;
                 args[0].op = Operand::Immediate(Immediate::Scalar(ptr.ptr.into())); // strip vtable
                 trace!("Patched self operand to {:#?}", args[0]);
                 // recurse with concrete function
@@ -455,7 +455,7 @@ impl<'a, 'mir, 'tcx, M: Machine<'a, 'mir, 'tcx>> EvalContext<'a, 'mir, 'tcx, M>
         };
 
         let ty = self.tcx.mk_unit(); // return type is ()
-        let dest = MPlaceTy::dangling(self.layout_of(ty)?, &self);
+        let dest = MPlaceTy::dangling(self.layout_of(ty)?, self);
 
         self.eval_fn_call(
             instance,
diff --git a/src/librustc_mir/interpret/traits.rs b/src/librustc_mir/interpret/traits.rs
index c189ec0ca5c..c5366a5ce6a 100644
--- a/src/librustc_mir/interpret/traits.rs
+++ b/src/librustc_mir/interpret/traits.rs
@@ -60,9 +60,9 @@ impl<'a, 'mir, 'tcx, M: Machine<'a, 'mir, 'tcx>> EvalContext<'a, 'mir, 'tcx, M>
         let drop = self.memory.create_fn_alloc(drop).with_default_tag();
         self.memory.write_ptr_sized(vtable, ptr_align, Scalar::Ptr(drop).into())?;
 
-        let size_ptr = vtable.offset(ptr_size, &self)?;
+        let size_ptr = vtable.offset(ptr_size, self)?;
         self.memory.write_ptr_sized(size_ptr, ptr_align, Scalar::from_uint(size, ptr_size).into())?;
-        let align_ptr = vtable.offset(ptr_size * 2, &self)?;
+        let align_ptr = vtable.offset(ptr_size * 2, self)?;
         self.memory.write_ptr_sized(align_ptr, ptr_align,
             Scalar::from_uint(align, ptr_size).into())?;
 
@@ -70,7 +70,7 @@ impl<'a, 'mir, 'tcx, M: Machine<'a, 'mir, 'tcx>> EvalContext<'a, 'mir, 'tcx, M>
             if let Some((def_id, substs)) = *method {
                 let instance = self.resolve(def_id, substs)?;
                 let fn_ptr = self.memory.create_fn_alloc(instance).with_default_tag();
-                let method_ptr = vtable.offset(ptr_size * (3 + i as u64), &self)?;
+                let method_ptr = vtable.offset(ptr_size * (3 + i as u64), self)?;
                 self.memory.write_ptr_sized(method_ptr, ptr_align, Scalar::Ptr(fn_ptr).into())?;
             }
         }
diff --git a/src/librustc_mir/transform/const_prop.rs b/src/librustc_mir/transform/const_prop.rs
index 24d9e761d97..52ef37ab40e 100644
--- a/src/librustc_mir/transform/const_prop.rs
+++ b/src/librustc_mir/transform/const_prop.rs
@@ -87,23 +87,23 @@ struct ConstPropagator<'a, 'mir, 'tcx:'a+'mir> {
     param_env: ParamEnv<'tcx>,
 }
 
-impl<'a, 'b, 'tcx> LayoutOf for &'a ConstPropagator<'a, 'b, 'tcx> {
+impl<'a, 'b, 'tcx> LayoutOf for ConstPropagator<'a, 'b, 'tcx> {
     type Ty = ty::Ty<'tcx>;
     type TyLayout = Result<TyLayout<'tcx>, LayoutError<'tcx>>;
 
-    fn layout_of(self, ty: ty::Ty<'tcx>) -> Self::TyLayout {
+    fn layout_of(&self, ty: ty::Ty<'tcx>) -> Self::TyLayout {
         self.tcx.layout_of(self.param_env.and(ty))
     }
 }
 
-impl<'a, 'b, 'tcx> HasDataLayout for &'a ConstPropagator<'a, 'b, 'tcx> {
+impl<'a, 'b, 'tcx> HasDataLayout for ConstPropagator<'a, 'b, 'tcx> {
     #[inline]
     fn data_layout(&self) -> &TargetDataLayout {
         &self.tcx.data_layout
     }
 }
 
-impl<'a, 'b, 'tcx> HasTyCtxt<'tcx> for &'a ConstPropagator<'a, 'b, 'tcx> {
+impl<'a, 'b, 'tcx> HasTyCtxt<'tcx> for ConstPropagator<'a, 'b, 'tcx> {
     #[inline]
     fn tcx<'c>(&'c self) -> TyCtxt<'c, 'tcx, 'tcx> {
         self.tcx
diff --git a/src/librustc_target/abi/call/aarch64.rs b/src/librustc_target/abi/call/aarch64.rs
index 90b5b97b51e..b4d393749c4 100644
--- a/src/librustc_target/abi/call/aarch64.rs
+++ b/src/librustc_target/abi/call/aarch64.rs
@@ -11,7 +11,7 @@
 use abi::call::{FnType, ArgType, Reg, RegKind, Uniform};
 use abi::{HasDataLayout, LayoutOf, TyLayout, TyLayoutMethods};
 
-fn is_homogeneous_aggregate<'a, Ty, C>(cx: C, arg: &mut ArgType<'a, Ty>)
+fn is_homogeneous_aggregate<'a, Ty, C>(cx: &C, arg: &mut ArgType<'a, Ty>)
                                      -> Option<Uniform>
     where Ty: TyLayoutMethods<'a, C> + Copy,
           C: LayoutOf<Ty = Ty, TyLayout = TyLayout<'a, Ty>> + HasDataLayout
@@ -41,7 +41,7 @@ fn is_homogeneous_aggregate<'a, Ty, C>(cx: C, arg: &mut ArgType<'a, Ty>)
     })
 }
 
-fn classify_ret_ty<'a, Ty, C>(cx: C, ret: &mut ArgType<'a, Ty>)
+fn classify_ret_ty<'a, Ty, C>(cx: &C, ret: &mut ArgType<'a, Ty>)
     where Ty: TyLayoutMethods<'a, C> + Copy,
           C: LayoutOf<Ty = Ty, TyLayout = TyLayout<'a, Ty>> + HasDataLayout
 {
@@ -75,7 +75,7 @@ fn classify_ret_ty<'a, Ty, C>(cx: C, ret: &mut ArgType<'a, Ty>)
     ret.make_indirect();
 }
 
-fn classify_arg_ty<'a, Ty, C>(cx: C, arg: &mut ArgType<'a, Ty>)
+fn classify_arg_ty<'a, Ty, C>(cx: &C, arg: &mut ArgType<'a, Ty>)
     where Ty: TyLayoutMethods<'a, C> + Copy,
           C: LayoutOf<Ty = Ty, TyLayout = TyLayout<'a, Ty>> + HasDataLayout
 {
@@ -109,7 +109,7 @@ fn classify_arg_ty<'a, Ty, C>(cx: C, arg: &mut ArgType<'a, Ty>)
     arg.make_indirect();
 }
 
-pub fn compute_abi_info<'a, Ty, C>(cx: C, fty: &mut FnType<'a, Ty>)
+pub fn compute_abi_info<'a, Ty, C>(cx: &C, fty: &mut FnType<'a, Ty>)
     where Ty: TyLayoutMethods<'a, C> + Copy,
           C: LayoutOf<Ty = Ty, TyLayout = TyLayout<'a, Ty>> + HasDataLayout
 {
diff --git a/src/librustc_target/abi/call/amdgpu.rs b/src/librustc_target/abi/call/amdgpu.rs
index 62462f04d8f..85789d7d4d7 100644
--- a/src/librustc_target/abi/call/amdgpu.rs
+++ b/src/librustc_target/abi/call/amdgpu.rs
@@ -11,21 +11,21 @@
 use abi::call::{ArgType, FnType, };
 use abi::{HasDataLayout, LayoutOf, TyLayout, TyLayoutMethods};
 
-fn classify_ret_ty<'a, Ty, C>(_tuncx: C, ret: &mut ArgType<'a, Ty>)
+fn classify_ret_ty<'a, Ty, C>(_cx: &C, ret: &mut ArgType<'a, Ty>)
   where Ty: TyLayoutMethods<'a, C> + Copy,
         C: LayoutOf<Ty = Ty, TyLayout = TyLayout<'a, Ty>> + HasDataLayout
 {
   ret.extend_integer_width_to(32);
 }
 
-fn classify_arg_ty<'a, Ty, C>(_cx: C, arg: &mut ArgType<'a, Ty>)
+fn classify_arg_ty<'a, Ty, C>(_cx: &C, arg: &mut ArgType<'a, Ty>)
   where Ty: TyLayoutMethods<'a, C> + Copy,
         C: LayoutOf<Ty = Ty, TyLayout = TyLayout<'a, Ty>> + HasDataLayout
 {
   arg.extend_integer_width_to(32);
 }
 
-pub fn compute_abi_info<'a, Ty, C>(cx: C, fty: &mut FnType<'a, Ty>)
+pub fn compute_abi_info<'a, Ty, C>(cx: &C, fty: &mut FnType<'a, Ty>)
   where Ty: TyLayoutMethods<'a, C> + Copy,
         C: LayoutOf<Ty = Ty, TyLayout = TyLayout<'a, Ty>> + HasDataLayout
 {
diff --git a/src/librustc_target/abi/call/arm.rs b/src/librustc_target/abi/call/arm.rs
index 249aad2d937..b4ffae7385a 100644
--- a/src/librustc_target/abi/call/arm.rs
+++ b/src/librustc_target/abi/call/arm.rs
@@ -12,7 +12,7 @@ use abi::call::{Conv, FnType, ArgType, Reg, RegKind, Uniform};
 use abi::{HasDataLayout, LayoutOf, TyLayout, TyLayoutMethods};
 use spec::HasTargetSpec;
 
-fn is_homogeneous_aggregate<'a, Ty, C>(cx: C, arg: &mut ArgType<'a, Ty>)
+fn is_homogeneous_aggregate<'a, Ty, C>(cx: &C, arg: &mut ArgType<'a, Ty>)
                                      -> Option<Uniform>
     where Ty: TyLayoutMethods<'a, C> + Copy,
           C: LayoutOf<Ty = Ty, TyLayout = TyLayout<'a, Ty>> + HasDataLayout
@@ -42,7 +42,7 @@ fn is_homogeneous_aggregate<'a, Ty, C>(cx: C, arg: &mut ArgType<'a, Ty>)
     })
 }
 
-fn classify_ret_ty<'a, Ty, C>(cx: C, ret: &mut ArgType<'a, Ty>, vfp: bool)
+fn classify_ret_ty<'a, Ty, C>(cx: &C, ret: &mut ArgType<'a, Ty>, vfp: bool)
     where Ty: TyLayoutMethods<'a, C> + Copy,
           C: LayoutOf<Ty = Ty, TyLayout = TyLayout<'a, Ty>> + HasDataLayout
 {
@@ -77,7 +77,7 @@ fn classify_ret_ty<'a, Ty, C>(cx: C, ret: &mut ArgType<'a, Ty>, vfp: bool)
     ret.make_indirect();
 }
 
-fn classify_arg_ty<'a, Ty, C>(cx: C, arg: &mut ArgType<'a, Ty>, vfp: bool)
+fn classify_arg_ty<'a, Ty, C>(cx: &C, arg: &mut ArgType<'a, Ty>, vfp: bool)
     where Ty: TyLayoutMethods<'a, C> + Copy,
           C: LayoutOf<Ty = Ty, TyLayout = TyLayout<'a, Ty>> + HasDataLayout
 {
@@ -101,7 +101,7 @@ fn classify_arg_ty<'a, Ty, C>(cx: C, arg: &mut ArgType<'a, Ty>, vfp: bool)
     });
 }
 
-pub fn compute_abi_info<'a, Ty, C>(cx: C, fty: &mut FnType<'a, Ty>)
+pub fn compute_abi_info<'a, Ty, C>(cx: &C, fty: &mut FnType<'a, Ty>)
     where Ty: TyLayoutMethods<'a, C> + Copy,
           C: LayoutOf<Ty = Ty, TyLayout = TyLayout<'a, Ty>> + HasDataLayout + HasTargetSpec
 {
diff --git a/src/librustc_target/abi/call/asmjs.rs b/src/librustc_target/abi/call/asmjs.rs
index 81d6f7b134b..3bd2594bdb9 100644
--- a/src/librustc_target/abi/call/asmjs.rs
+++ b/src/librustc_target/abi/call/asmjs.rs
@@ -16,7 +16,7 @@ use abi::{HasDataLayout, LayoutOf, TyLayout, TyLayoutMethods};
 // See the https://github.com/kripken/emscripten-fastcomp-clang repository.
 // The class `EmscriptenABIInfo` in `/lib/CodeGen/TargetInfo.cpp` contains the ABI definitions.
 
-fn classify_ret_ty<'a, Ty, C>(cx: C, ret: &mut ArgType<'a, Ty>)
+fn classify_ret_ty<'a, Ty, C>(cx: &C, ret: &mut ArgType<'a, Ty>)
     where Ty: TyLayoutMethods<'a, C> + Copy,
           C: LayoutOf<Ty = Ty, TyLayout = TyLayout<'a, Ty>> + HasDataLayout
 {
@@ -42,7 +42,7 @@ fn classify_arg_ty<Ty>(arg: &mut ArgType<Ty>) {
     }
 }
 
-pub fn compute_abi_info<'a, Ty, C>(cx: C, fty: &mut FnType<'a, Ty>)
+pub fn compute_abi_info<'a, Ty, C>(cx: &C, fty: &mut FnType<'a, Ty>)
     where Ty: TyLayoutMethods<'a, C> + Copy,
           C: LayoutOf<Ty = Ty, TyLayout = TyLayout<'a, Ty>> + HasDataLayout
 {
diff --git a/src/librustc_target/abi/call/mips.rs b/src/librustc_target/abi/call/mips.rs
index 1e8af52e3e8..a40cb6c76f0 100644
--- a/src/librustc_target/abi/call/mips.rs
+++ b/src/librustc_target/abi/call/mips.rs
@@ -11,7 +11,7 @@
 use abi::call::{ArgType, FnType, Reg, Uniform};
 use abi::{HasDataLayout, LayoutOf, Size, TyLayoutMethods};
 
-fn classify_ret_ty<'a, Ty, C>(cx: C, ret: &mut ArgType<Ty>, offset: &mut Size)
+fn classify_ret_ty<'a, Ty, C>(cx: &C, ret: &mut ArgType<Ty>, offset: &mut Size)
     where Ty: TyLayoutMethods<'a, C>, C: LayoutOf<Ty = Ty> + HasDataLayout
 {
     if !ret.layout.is_aggregate() {
@@ -22,7 +22,7 @@ fn classify_ret_ty<'a, Ty, C>(cx: C, ret: &mut ArgType<Ty>, offset: &mut Size)
     }
 }
 
-fn classify_arg_ty<'a, Ty, C>(cx: C, arg: &mut ArgType<Ty>, offset: &mut Size)
+fn classify_arg_ty<'a, Ty, C>(cx: &C, arg: &mut ArgType<Ty>, offset: &mut Size)
     where Ty: TyLayoutMethods<'a, C>, C: LayoutOf<Ty = Ty> + HasDataLayout
 {
     let dl = cx.data_layout();
@@ -44,7 +44,7 @@ fn classify_arg_ty<'a, Ty, C>(cx: C, arg: &mut ArgType<Ty>, offset: &mut Size)
     *offset = offset.abi_align(align) + size.abi_align(align);
 }
 
-pub fn compute_abi_info<'a, Ty, C>(cx: C, fty: &mut FnType<Ty>)
+pub fn compute_abi_info<'a, Ty, C>(cx: &C, fty: &mut FnType<Ty>)
     where Ty: TyLayoutMethods<'a, C>, C: LayoutOf<Ty = Ty> + HasDataLayout
 {
     let mut offset = Size::ZERO;
diff --git a/src/librustc_target/abi/call/mips64.rs b/src/librustc_target/abi/call/mips64.rs
index 8e2dd99696e..adf5a3c94ea 100644
--- a/src/librustc_target/abi/call/mips64.rs
+++ b/src/librustc_target/abi/call/mips64.rs
@@ -27,7 +27,7 @@ fn extend_integer_width_mips<Ty>(arg: &mut ArgType<Ty>, bits: u64) {
     arg.extend_integer_width_to(bits);
 }
 
-fn float_reg<'a, Ty, C>(cx: C, ret: &ArgType<'a, Ty>, i: usize) -> Option<Reg>
+fn float_reg<'a, Ty, C>(cx: &C, ret: &ArgType<'a, Ty>, i: usize) -> Option<Reg>
     where Ty: TyLayoutMethods<'a, C> + Copy,
           C: LayoutOf<Ty = Ty, TyLayout = TyLayout<'a, Ty>> + HasDataLayout
 {
@@ -41,7 +41,7 @@ fn float_reg<'a, Ty, C>(cx: C, ret: &ArgType<'a, Ty>, i: usize) -> Option<Reg>
     }
 }
 
-fn classify_ret_ty<'a, Ty, C>(cx: C, ret: &mut ArgType<'a, Ty>)
+fn classify_ret_ty<'a, Ty, C>(cx: &C, ret: &mut ArgType<'a, Ty>)
     where Ty: TyLayoutMethods<'a, C> + Copy,
           C: LayoutOf<Ty = Ty, TyLayout = TyLayout<'a, Ty>> + HasDataLayout
 {
@@ -83,7 +83,7 @@ fn classify_ret_ty<'a, Ty, C>(cx: C, ret: &mut ArgType<'a, Ty>)
     }
 }
 
-fn classify_arg_ty<'a, Ty, C>(cx: C, arg: &mut ArgType<'a, Ty>)
+fn classify_arg_ty<'a, Ty, C>(cx: &C, arg: &mut ArgType<'a, Ty>)
     where Ty: TyLayoutMethods<'a, C> + Copy,
           C: LayoutOf<Ty = Ty, TyLayout = TyLayout<'a, Ty>> + HasDataLayout
 {
@@ -151,7 +151,7 @@ fn classify_arg_ty<'a, Ty, C>(cx: C, arg: &mut ArgType<'a, Ty>)
     });
 }
 
-pub fn compute_abi_info<'a, Ty, C>(cx: C, fty: &mut FnType<'a, Ty>)
+pub fn compute_abi_info<'a, Ty, C>(cx: &C, fty: &mut FnType<'a, Ty>)
     where Ty: TyLayoutMethods<'a, C> + Copy,
           C: LayoutOf<Ty = Ty, TyLayout = TyLayout<'a, Ty>> + HasDataLayout
 {
diff --git a/src/librustc_target/abi/call/mod.rs b/src/librustc_target/abi/call/mod.rs
index 788497a378f..8f9ef2544e6 100644
--- a/src/librustc_target/abi/call/mod.rs
+++ b/src/librustc_target/abi/call/mod.rs
@@ -137,7 +137,7 @@ impl Reg {
 }
 
 impl Reg {
-    pub fn align<C: HasDataLayout>(&self, cx: C) -> Align {
+    pub fn align<C: HasDataLayout>(&self, cx: &C) -> Align {
         let dl = cx.data_layout();
         match self.kind {
             RegKind::Integer => {
@@ -188,7 +188,7 @@ impl From<Reg> for Uniform {
 }
 
 impl Uniform {
-    pub fn align<C: HasDataLayout>(&self, cx: C) -> Align {
+    pub fn align<C: HasDataLayout>(&self, cx: &C) -> Align {
         self.unit.align(cx)
     }
 }
@@ -225,12 +225,12 @@ impl CastTarget {
         }
     }
 
-    pub fn size<C: HasDataLayout>(&self, cx: C) -> Size {
+    pub fn size<C: HasDataLayout>(&self, cx: &C) -> Size {
         (self.prefix_chunk * self.prefix.iter().filter(|x| x.is_some()).count() as u64)
              .abi_align(self.rest.align(cx)) + self.rest.total
     }
 
-    pub fn align<C: HasDataLayout>(&self, cx: C) -> Align {
+    pub fn align<C: HasDataLayout>(&self, cx: &C) -> Align {
         self.prefix.iter()
             .filter_map(|x| x.map(|kind| Reg { kind, size: self.prefix_chunk }.align(cx)))
             .fold(cx.data_layout().aggregate_align.max(self.rest.align(cx)),
@@ -249,8 +249,8 @@ impl<'a, Ty> TyLayout<'a, Ty> {
         }
     }
 
-    fn homogeneous_aggregate<C>(&self, cx: C) -> Option<Reg>
-        where Ty: TyLayoutMethods<'a, C> + Copy, C: LayoutOf<Ty = Ty, TyLayout = Self> + Copy
+    fn homogeneous_aggregate<C>(&self, cx: &C) -> Option<Reg>
+        where Ty: TyLayoutMethods<'a, C> + Copy, C: LayoutOf<Ty = Ty, TyLayout = Self>
     {
         match self.abi {
             Abi::Uninhabited => None,
@@ -483,7 +483,7 @@ pub struct FnType<'a, Ty> {
 }
 
 impl<'a, Ty> FnType<'a, Ty> {
-    pub fn adjust_for_cabi<C>(&mut self, cx: C, abi: ::spec::abi::Abi) -> Result<(), String>
+    pub fn adjust_for_cabi<C>(&mut self, cx: &C, abi: ::spec::abi::Abi) -> Result<(), String>
         where Ty: TyLayoutMethods<'a, C> + Copy,
               C: LayoutOf<Ty = Ty, TyLayout = TyLayout<'a, Ty>> + HasDataLayout + HasTargetSpec
     {
diff --git a/src/librustc_target/abi/call/powerpc.rs b/src/librustc_target/abi/call/powerpc.rs
index 3be3034143a..b9b012020b7 100644
--- a/src/librustc_target/abi/call/powerpc.rs
+++ b/src/librustc_target/abi/call/powerpc.rs
@@ -11,7 +11,7 @@
 use abi::call::{ArgType, FnType, Reg, Uniform};
 use abi::{HasDataLayout, LayoutOf, Size, TyLayoutMethods};
 
-fn classify_ret_ty<'a, Ty, C>(cx: C, ret: &mut ArgType<Ty>, offset: &mut Size)
+fn classify_ret_ty<'a, Ty, C>(cx: &C, ret: &mut ArgType<Ty>, offset: &mut Size)
     where Ty: TyLayoutMethods<'a, C>, C: LayoutOf<Ty = Ty> + HasDataLayout
 {
     if !ret.layout.is_aggregate() {
@@ -22,7 +22,7 @@ fn classify_ret_ty<'a, Ty, C>(cx: C, ret: &mut ArgType<Ty>, offset: &mut Size)
     }
 }
 
-fn classify_arg_ty<'a, Ty, C>(cx: C, arg: &mut ArgType<Ty>, offset: &mut Size)
+fn classify_arg_ty<'a, Ty, C>(cx: &C, arg: &mut ArgType<Ty>, offset: &mut Size)
     where Ty: TyLayoutMethods<'a, C>, C: LayoutOf<Ty = Ty> + HasDataLayout
 {
     let dl = cx.data_layout();
@@ -44,7 +44,7 @@ fn classify_arg_ty<'a, Ty, C>(cx: C, arg: &mut ArgType<Ty>, offset: &mut Size)
     *offset = offset.abi_align(align) + size.abi_align(align);
 }
 
-pub fn compute_abi_info<'a, Ty, C>(cx: C, fty: &mut FnType<Ty>)
+pub fn compute_abi_info<'a, Ty, C>(cx: &C, fty: &mut FnType<Ty>)
     where Ty: TyLayoutMethods<'a, C>, C: LayoutOf<Ty = Ty> + HasDataLayout
 {
     let mut offset = Size::ZERO;
diff --git a/src/librustc_target/abi/call/powerpc64.rs b/src/librustc_target/abi/call/powerpc64.rs
index 0c5ec77a398..80a4d693dc3 100644
--- a/src/librustc_target/abi/call/powerpc64.rs
+++ b/src/librustc_target/abi/call/powerpc64.rs
@@ -22,7 +22,7 @@ enum ABI {
 }
 use self::ABI::*;
 
-fn is_homogeneous_aggregate<'a, Ty, C>(cx: C, arg: &mut ArgType<'a, Ty>, abi: ABI)
+fn is_homogeneous_aggregate<'a, Ty, C>(cx: &C, arg: &mut ArgType<'a, Ty>, abi: ABI)
                                        -> Option<Uniform>
     where Ty: TyLayoutMethods<'a, C> + Copy,
           C: LayoutOf<Ty = Ty, TyLayout = TyLayout<'a, Ty>> + HasDataLayout
@@ -52,7 +52,7 @@ fn is_homogeneous_aggregate<'a, Ty, C>(cx: C, arg: &mut ArgType<'a, Ty>, abi: AB
     })
 }
 
-fn classify_ret_ty<'a, Ty, C>(cx: C, ret: &mut ArgType<'a, Ty>, abi: ABI)
+fn classify_ret_ty<'a, Ty, C>(cx: &C, ret: &mut ArgType<'a, Ty>, abi: ABI)
     where Ty: TyLayoutMethods<'a, C> + Copy,
           C: LayoutOf<Ty = Ty, TyLayout = TyLayout<'a, Ty>> + HasDataLayout
 {
@@ -95,7 +95,7 @@ fn classify_ret_ty<'a, Ty, C>(cx: C, ret: &mut ArgType<'a, Ty>, abi: ABI)
     ret.make_indirect();
 }
 
-fn classify_arg_ty<'a, Ty, C>(cx: C, arg: &mut ArgType<'a, Ty>, abi: ABI)
+fn classify_arg_ty<'a, Ty, C>(cx: &C, arg: &mut ArgType<'a, Ty>, abi: ABI)
     where Ty: TyLayoutMethods<'a, C> + Copy,
           C: LayoutOf<Ty = Ty, TyLayout = TyLayout<'a, Ty>> + HasDataLayout
 {
@@ -134,7 +134,7 @@ fn classify_arg_ty<'a, Ty, C>(cx: C, arg: &mut ArgType<'a, Ty>, abi: ABI)
     });
 }
 
-pub fn compute_abi_info<'a, Ty, C>(cx: C, fty: &mut FnType<'a, Ty>)
+pub fn compute_abi_info<'a, Ty, C>(cx: &C, fty: &mut FnType<'a, Ty>)
     where Ty: TyLayoutMethods<'a, C> + Copy,
           C: LayoutOf<Ty = Ty, TyLayout = TyLayout<'a, Ty>> + HasDataLayout
 {
diff --git a/src/librustc_target/abi/call/s390x.rs b/src/librustc_target/abi/call/s390x.rs
index 37be6ea41c6..d6d8ea71918 100644
--- a/src/librustc_target/abi/call/s390x.rs
+++ b/src/librustc_target/abi/call/s390x.rs
@@ -24,7 +24,7 @@ fn classify_ret_ty<'a, Ty, C>(ret: &mut ArgType<Ty>)
     }
 }
 
-fn is_single_fp_element<'a, Ty, C>(cx: C, layout: TyLayout<'a, Ty>) -> bool
+fn is_single_fp_element<'a, Ty, C>(cx: &C, layout: TyLayout<'a, Ty>) -> bool
     where Ty: TyLayoutMethods<'a, C>,
           C: LayoutOf<Ty = Ty, TyLayout = TyLayout<'a, Ty>> + HasDataLayout
 {
@@ -41,7 +41,7 @@ fn is_single_fp_element<'a, Ty, C>(cx: C, layout: TyLayout<'a, Ty>) -> bool
     }
 }
 
-fn classify_arg_ty<'a, Ty, C>(cx: C, arg: &mut ArgType<'a, Ty>)
+fn classify_arg_ty<'a, Ty, C>(cx: &C, arg: &mut ArgType<'a, Ty>)
     where Ty: TyLayoutMethods<'a, C> + Copy,
           C: LayoutOf<Ty = Ty, TyLayout = TyLayout<'a, Ty>> + HasDataLayout
 {
@@ -67,7 +67,7 @@ fn classify_arg_ty<'a, Ty, C>(cx: C, arg: &mut ArgType<'a, Ty>)
     }
 }
 
-pub fn compute_abi_info<'a, Ty, C>(cx: C, fty: &mut FnType<'a, Ty>)
+pub fn compute_abi_info<'a, Ty, C>(cx: &C, fty: &mut FnType<'a, Ty>)
     where Ty: TyLayoutMethods<'a, C> + Copy,
           C: LayoutOf<Ty = Ty, TyLayout = TyLayout<'a, Ty>> + HasDataLayout
 {
diff --git a/src/librustc_target/abi/call/sparc.rs b/src/librustc_target/abi/call/sparc.rs
index 1e8af52e3e8..a40cb6c76f0 100644
--- a/src/librustc_target/abi/call/sparc.rs
+++ b/src/librustc_target/abi/call/sparc.rs
@@ -11,7 +11,7 @@
 use abi::call::{ArgType, FnType, Reg, Uniform};
 use abi::{HasDataLayout, LayoutOf, Size, TyLayoutMethods};
 
-fn classify_ret_ty<'a, Ty, C>(cx: C, ret: &mut ArgType<Ty>, offset: &mut Size)
+fn classify_ret_ty<'a, Ty, C>(cx: &C, ret: &mut ArgType<Ty>, offset: &mut Size)
     where Ty: TyLayoutMethods<'a, C>, C: LayoutOf<Ty = Ty> + HasDataLayout
 {
     if !ret.layout.is_aggregate() {
@@ -22,7 +22,7 @@ fn classify_ret_ty<'a, Ty, C>(cx: C, ret: &mut ArgType<Ty>, offset: &mut Size)
     }
 }
 
-fn classify_arg_ty<'a, Ty, C>(cx: C, arg: &mut ArgType<Ty>, offset: &mut Size)
+fn classify_arg_ty<'a, Ty, C>(cx: &C, arg: &mut ArgType<Ty>, offset: &mut Size)
     where Ty: TyLayoutMethods<'a, C>, C: LayoutOf<Ty = Ty> + HasDataLayout
 {
     let dl = cx.data_layout();
@@ -44,7 +44,7 @@ fn classify_arg_ty<'a, Ty, C>(cx: C, arg: &mut ArgType<Ty>, offset: &mut Size)
     *offset = offset.abi_align(align) + size.abi_align(align);
 }
 
-pub fn compute_abi_info<'a, Ty, C>(cx: C, fty: &mut FnType<Ty>)
+pub fn compute_abi_info<'a, Ty, C>(cx: &C, fty: &mut FnType<Ty>)
     where Ty: TyLayoutMethods<'a, C>, C: LayoutOf<Ty = Ty> + HasDataLayout
 {
     let mut offset = Size::ZERO;
diff --git a/src/librustc_target/abi/call/sparc64.rs b/src/librustc_target/abi/call/sparc64.rs
index a58aebc2ff0..a609feb3f57 100644
--- a/src/librustc_target/abi/call/sparc64.rs
+++ b/src/librustc_target/abi/call/sparc64.rs
@@ -13,7 +13,7 @@
 use abi::call::{FnType, ArgType, Reg, RegKind, Uniform};
 use abi::{HasDataLayout, LayoutOf, TyLayout, TyLayoutMethods};
 
-fn is_homogeneous_aggregate<'a, Ty, C>(cx: C, arg: &mut ArgType<'a, Ty>)
+fn is_homogeneous_aggregate<'a, Ty, C>(cx: &C, arg: &mut ArgType<'a, Ty>)
                                      -> Option<Uniform>
     where Ty: TyLayoutMethods<'a, C> + Copy,
           C: LayoutOf<Ty = Ty, TyLayout = TyLayout<'a, Ty>> + HasDataLayout
@@ -41,7 +41,7 @@ fn is_homogeneous_aggregate<'a, Ty, C>(cx: C, arg: &mut ArgType<'a, Ty>)
     })
 }
 
-fn classify_ret_ty<'a, Ty, C>(cx: C, ret: &mut ArgType<'a, Ty>)
+fn classify_ret_ty<'a, Ty, C>(cx: &C, ret: &mut ArgType<'a, Ty>)
     where Ty: TyLayoutMethods<'a, C> + Copy,
           C: LayoutOf<Ty = Ty, TyLayout = TyLayout<'a, Ty>> + HasDataLayout
 {
@@ -69,7 +69,7 @@ fn classify_ret_ty<'a, Ty, C>(cx: C, ret: &mut ArgType<'a, Ty>)
     ret.make_indirect();
 }
 
-fn classify_arg_ty<'a, Ty, C>(cx: C, arg: &mut ArgType<'a, Ty>)
+fn classify_arg_ty<'a, Ty, C>(cx: &C, arg: &mut ArgType<'a, Ty>)
     where Ty: TyLayoutMethods<'a, C> + Copy,
           C: LayoutOf<Ty = Ty, TyLayout = TyLayout<'a, Ty>> + HasDataLayout
 {
@@ -95,7 +95,7 @@ fn classify_arg_ty<'a, Ty, C>(cx: C, arg: &mut ArgType<'a, Ty>)
     });
 }
 
-pub fn compute_abi_info<'a, Ty, C>(cx: C, fty: &mut FnType<'a, Ty>)
+pub fn compute_abi_info<'a, Ty, C>(cx: &C, fty: &mut FnType<'a, Ty>)
     where Ty: TyLayoutMethods<'a, C> + Copy,
           C: LayoutOf<Ty = Ty, TyLayout = TyLayout<'a, Ty>> + HasDataLayout
 {
diff --git a/src/librustc_target/abi/call/x86.rs b/src/librustc_target/abi/call/x86.rs
index 1dcaafcf77f..9a95e5b192b 100644
--- a/src/librustc_target/abi/call/x86.rs
+++ b/src/librustc_target/abi/call/x86.rs
@@ -18,7 +18,7 @@ pub enum Flavor {
     Fastcall
 }
 
-fn is_single_fp_element<'a, Ty, C>(cx: C, layout: TyLayout<'a, Ty>) -> bool
+fn is_single_fp_element<'a, Ty, C>(cx: &C, layout: TyLayout<'a, Ty>) -> bool
     where Ty: TyLayoutMethods<'a, C> + Copy,
           C: LayoutOf<Ty = Ty, TyLayout = TyLayout<'a, Ty>> + HasDataLayout
 {
@@ -35,7 +35,7 @@ fn is_single_fp_element<'a, Ty, C>(cx: C, layout: TyLayout<'a, Ty>) -> bool
     }
 }
 
-pub fn compute_abi_info<'a, Ty, C>(cx: C, fty: &mut FnType<'a, Ty>, flavor: Flavor)
+pub fn compute_abi_info<'a, Ty, C>(cx: &C, fty: &mut FnType<'a, Ty>, flavor: Flavor)
     where Ty: TyLayoutMethods<'a, C> + Copy,
           C: LayoutOf<Ty = Ty, TyLayout = TyLayout<'a, Ty>> + HasDataLayout + HasTargetSpec
 {
diff --git a/src/librustc_target/abi/call/x86_64.rs b/src/librustc_target/abi/call/x86_64.rs
index eade086ec48..4c944650893 100644
--- a/src/librustc_target/abi/call/x86_64.rs
+++ b/src/librustc_target/abi/call/x86_64.rs
@@ -31,12 +31,12 @@ struct Memory;
 const LARGEST_VECTOR_SIZE: usize = 512;
 const MAX_EIGHTBYTES: usize = LARGEST_VECTOR_SIZE / 64;
 
-fn classify_arg<'a, Ty, C>(cx: C, arg: &ArgType<'a, Ty>)
+fn classify_arg<'a, Ty, C>(cx: &C, arg: &ArgType<'a, Ty>)
                           -> Result<[Option<Class>; MAX_EIGHTBYTES], Memory>
     where Ty: TyLayoutMethods<'a, C> + Copy,
           C: LayoutOf<Ty = Ty, TyLayout = TyLayout<'a, Ty>> + HasDataLayout
 {
-    fn classify<'a, Ty, C>(cx: C, layout: TyLayout<'a, Ty>,
+    fn classify<'a, Ty, C>(cx: &C, layout: TyLayout<'a, Ty>,
                           cls: &mut [Option<Class>], off: Size) -> Result<(), Memory>
         where Ty: TyLayoutMethods<'a, C> + Copy,
             C: LayoutOf<Ty = Ty, TyLayout = TyLayout<'a, Ty>> + HasDataLayout
@@ -178,7 +178,7 @@ fn cast_target(cls: &[Option<Class>], size: Size) -> CastTarget {
     target
 }
 
-pub fn compute_abi_info<'a, Ty, C>(cx: C, fty: &mut FnType<'a, Ty>)
+pub fn compute_abi_info<'a, Ty, C>(cx: &C, fty: &mut FnType<'a, Ty>)
     where Ty: TyLayoutMethods<'a, C> + Copy,
           C: LayoutOf<Ty = Ty, TyLayout = TyLayout<'a, Ty>> + HasDataLayout
 {
diff --git a/src/librustc_target/abi/mod.rs b/src/librustc_target/abi/mod.rs
index 1a5d2801af0..c7d0469e556 100644
--- a/src/librustc_target/abi/mod.rs
+++ b/src/librustc_target/abi/mod.rs
@@ -203,11 +203,11 @@ impl TargetDataLayout {
     }
 }
 
-pub trait HasDataLayout: Copy {
+pub trait HasDataLayout {
     fn data_layout(&self) -> &TargetDataLayout;
 }
 
-impl<'a> HasDataLayout for &'a TargetDataLayout {
+impl HasDataLayout for TargetDataLayout {
     fn data_layout(&self) -> &TargetDataLayout {
         self
     }
@@ -267,7 +267,7 @@ impl Size {
     }
 
     #[inline]
-    pub fn checked_add<C: HasDataLayout>(self, offset: Size, cx: C) -> Option<Size> {
+    pub fn checked_add<C: HasDataLayout>(self, offset: Size, cx: &C) -> Option<Size> {
         let dl = cx.data_layout();
 
         let bytes = self.bytes().checked_add(offset.bytes())?;
@@ -280,7 +280,7 @@ impl Size {
     }
 
     #[inline]
-    pub fn checked_mul<C: HasDataLayout>(self, count: u64, cx: C) -> Option<Size> {
+    pub fn checked_mul<C: HasDataLayout>(self, count: u64, cx: &C) -> Option<Size> {
         let dl = cx.data_layout();
 
         let bytes = self.bytes().checked_mul(count)?;
@@ -457,7 +457,7 @@ impl Integer {
         }
     }
 
-    pub fn align<C: HasDataLayout>(self, cx: C) -> Align {
+    pub fn align<C: HasDataLayout>(self, cx: &C) -> Align {
         let dl = cx.data_layout();
 
         match self {
@@ -492,7 +492,7 @@ impl Integer {
     }
 
     /// Find the smallest integer with the given alignment.
-    pub fn for_abi_align<C: HasDataLayout>(cx: C, align: Align) -> Option<Integer> {
+    pub fn for_abi_align<C: HasDataLayout>(cx: &C, align: Align) -> Option<Integer> {
         let dl = cx.data_layout();
 
         let wanted = align.abi();
@@ -505,7 +505,7 @@ impl Integer {
     }
 
     /// Find the largest integer with the given alignment or less.
-    pub fn approximate_abi_align<C: HasDataLayout>(cx: C, align: Align) -> Integer {
+    pub fn approximate_abi_align<C: HasDataLayout>(cx: &C, align: Align) -> Integer {
         let dl = cx.data_layout();
 
         let wanted = align.abi();
@@ -571,7 +571,7 @@ pub enum Primitive {
 }
 
 impl<'a, 'tcx> Primitive {
-    pub fn size<C: HasDataLayout>(self, cx: C) -> Size {
+    pub fn size<C: HasDataLayout>(self, cx: &C) -> Size {
         let dl = cx.data_layout();
 
         match self {
@@ -582,7 +582,7 @@ impl<'a, 'tcx> Primitive {
         }
     }
 
-    pub fn align<C: HasDataLayout>(self, cx: C) -> Align {
+    pub fn align<C: HasDataLayout>(self, cx: &C) -> Align {
         let dl = cx.data_layout();
 
         match self {
@@ -642,7 +642,7 @@ impl Scalar {
     /// Returns the valid range as a `x..y` range.
     ///
     /// If `x` and `y` are equal, the range is full, not empty.
-    pub fn valid_range_exclusive<C: HasDataLayout>(&self, cx: C) -> Range<u128> {
+    pub fn valid_range_exclusive<C: HasDataLayout>(&self, cx: &C) -> Range<u128> {
         // For a (max) value of -1, max will be `-1 as usize`, which overflows.
         // However, that is fine here (it would still represent the full range),
         // i.e., if the range is everything.
@@ -854,7 +854,7 @@ pub struct LayoutDetails {
 }
 
 impl LayoutDetails {
-    pub fn scalar<C: HasDataLayout>(cx: C, scalar: Scalar) -> Self {
+    pub fn scalar<C: HasDataLayout>(cx: &C, scalar: Scalar) -> Self {
         let size = scalar.value.size(cx);
         let align = scalar.value.align(cx);
         LayoutDetails {
@@ -891,20 +891,20 @@ pub trait LayoutOf {
     type Ty;
     type TyLayout;
 
-    fn layout_of(self, ty: Self::Ty) -> Self::TyLayout;
+    fn layout_of(&self, ty: Self::Ty) -> Self::TyLayout;
 }
 
 pub trait TyLayoutMethods<'a, C: LayoutOf<Ty = Self>>: Sized {
-    fn for_variant(this: TyLayout<'a, Self>, cx: C, variant_index: usize) -> TyLayout<'a, Self>;
-    fn field(this: TyLayout<'a, Self>, cx: C, i: usize) -> C::TyLayout;
+    fn for_variant(this: TyLayout<'a, Self>, cx: &C, variant_index: usize) -> TyLayout<'a, Self>;
+    fn field(this: TyLayout<'a, Self>, cx: &C, i: usize) -> C::TyLayout;
 }
 
 impl<'a, Ty> TyLayout<'a, Ty> {
-    pub fn for_variant<C>(self, cx: C, variant_index: usize) -> Self
+    pub fn for_variant<C>(self, cx: &C, variant_index: usize) -> Self
     where Ty: TyLayoutMethods<'a, C>, C: LayoutOf<Ty = Ty> {
         Ty::for_variant(self, cx, variant_index)
     }
-    pub fn field<C>(self, cx: C, i: usize) -> C::TyLayout
+    pub fn field<C>(self, cx: &C, i: usize) -> C::TyLayout
     where Ty: TyLayoutMethods<'a, C>, C: LayoutOf<Ty = Ty> {
         Ty::field(self, cx, i)
     }
diff --git a/src/librustc_target/spec/mod.rs b/src/librustc_target/spec/mod.rs
index 49b4d6ec0f9..c8af81c02ea 100644
--- a/src/librustc_target/spec/mod.rs
+++ b/src/librustc_target/spec/mod.rs
@@ -444,11 +444,11 @@ pub struct Target {
     pub options: TargetOptions,
 }
 
-pub trait HasTargetSpec: Copy {
+pub trait HasTargetSpec {
     fn target_spec(&self) -> &Target;
 }
 
-impl<'a> HasTargetSpec for &'a Target {
+impl HasTargetSpec for Target {
     fn target_spec(&self) -> &Target {
         self
     }