Fix cranelift build

compiler/rustc_codegen_cranelift/src/base.rs

@@ -499,7 +499,7 @@ fn codegen_stmt<'tcx>(
                         UnOp::Neg => match layout.ty.kind() {
                             ty::Int(IntTy::I128) => {
                                 // FIXME remove this case once ineg.i128 works
-                                let zero = CValue::const_val(fx, layout, 0);
+                                let zero = CValue::const_val(fx, layout, ty::ScalarInt::null(layout.size));
                                 crate::num::codegen_int_binop(fx, BinOp::Sub, zero, operand)
                             }
                             ty::Int(_) => CValue::by_val(fx.bcx.ins().ineg(val), layout),
@@ -592,6 +592,7 @@ fn is_fat_ptr<'tcx>(
                                 } else {
                                     discr.val
                                 };
+                                let discr = discr.into();
 
                                 let discr = CValue::const_val(fx, fx.layout_of(to_ty), discr);
                                 lval.write_cvalue(fx, discr);

compiler/rustc_codegen_cranelift/src/constant.rs

@@ -186,9 +186,8 @@ pub(crate) fn codegen_const_value<'tcx>(
             }
 
             match x {
-                Scalar::Raw { data, size } => {
-                    assert_eq!(u64::from(size), layout.size.bytes());
-                    CValue::const_val(fx, layout, data)
+                Scalar::Raw(int) => {
+                    CValue::const_val(fx, layout, int)
                 }
                 Scalar::Ptr(ptr) => {
                     let alloc_kind = fx.tcx.get_global_alloc(ptr.alloc_id);

compiler/rustc_codegen_cranelift/src/discriminant.rs

@@ -30,7 +30,8 @@ pub(crate) fn codegen_set_discriminant<'tcx>(
                 .ty
                 .discriminant_for_variant(fx.tcx, variant_index)
                 .unwrap()
-                .val;
+                .val
+                .into();
             let discr = CValue::const_val(fx, ptr.layout(), to);
             ptr.write_cvalue(fx, discr);
         }
@@ -49,7 +50,7 @@ pub(crate) fn codegen_set_discriminant<'tcx>(
                 let niche = place.place_field(fx, mir::Field::new(tag_field));
                 let niche_value = variant_index.as_u32() - niche_variants.start().as_u32();
                 let niche_value = u128::from(niche_value).wrapping_add(niche_start);
-                let niche_llval = CValue::const_val(fx, niche.layout(), niche_value);
+                let niche_llval = CValue::const_val(fx, niche.layout(), niche_value.into());
                 niche.write_cvalue(fx, niche_llval);
             }
         }
@@ -77,7 +78,7 @@ pub(crate) fn codegen_get_discriminant<'tcx>(
                 .ty
                 .discriminant_for_variant(fx.tcx, *index)
                 .map_or(u128::from(index.as_u32()), |discr| discr.val);
-            return CValue::const_val(fx, dest_layout, discr_val);
+            return CValue::const_val(fx, dest_layout, discr_val.into());
         }
         Variants::Multiple {
             tag,

compiler/rustc_codegen_cranelift/src/intrinsics/mod.rs

@@ -1064,7 +1064,8 @@ fn swap(bcx: &mut FunctionBuilder<'_>, v: Value) -> Value {
 
             fx.bcx.ins().call_indirect(f_sig, f, &[data]);
 
-            let ret_val = CValue::const_val(fx, ret.layout(), 0);
+            let layout = ret.layout();
+            let ret_val = CValue::const_val(fx, layout, ty::ScalarInt::null(layout.size));
             ret.write_cvalue(fx, ret_val);
         };
 

compiler/rustc_codegen_cranelift/src/value_and_place.rs

@@ -231,15 +231,16 @@ pub(crate) fn unsize_value(
     pub(crate) fn const_val(
         fx: &mut FunctionCx<'_, 'tcx, impl Module>,
         layout: TyAndLayout<'tcx>,
-        const_val: u128,
+        const_val: ty::ScalarInt,
     ) -> CValue<'tcx> {
+        assert_eq!(const_val.size(), layout.size);
         use cranelift_codegen::ir::immediates::{Ieee32, Ieee64};
 
         let clif_ty = fx.clif_type(layout.ty).unwrap();
 
         if let ty::Bool = layout.ty.kind() {
             assert!(
-                const_val == 0 || const_val == 1,
+                const_val == ty::ScalarInt::FALSE || const_val == ty::ScalarInt::TRUE,
                 "Invalid bool 0x{:032X}",
                 const_val
             );
@@ -247,6 +248,7 @@ pub(crate) fn const_val(
 
         let val = match layout.ty.kind() {
             ty::Uint(UintTy::U128) | ty::Int(IntTy::I128) => {
+                let const_val = const_val.to_bits(layout.size).unwrap();
                 let lsb = fx.bcx.ins().iconst(types::I64, const_val as u64 as i64);
                 let msb = fx
                     .bcx

compiler/rustc_middle/src/ty/consts/int.rs

@@ -353,3 +353,17 @@ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         write!(f, "{:01$x}", { self.data }, self.size as usize * 2)
     }
 }
+
+impl fmt::UpperHex for ScalarInt {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        self.check_data();
+        // Format as hex number wide enough to fit any value of the given `size`.
+        // So data=20, size=1 will be "0x14", but with size=4 it'll be "0x00000014".
+        // Using a block `{self.data}` here to force a copy instead of using `self.data`
+        // directly, because `write!` takes references to its formatting arguments and
+        // would thus borrow `self.data`. Since `Self`
+        // is a packed struct, that would create a possibly unaligned reference, which
+        // is UB on a lot of platforms.
+        write!(f, "{:01$X}", { self.data }, self.size as usize * 2)
+    }
+}