Fix cast_possible_wrap and cast_sign_loss warnings

Author: devonhollowood

clippy_lints/src/consts.rs

@@ -230,6 +230,7 @@ impl<'c, 'cc> ConstEvalLateContext<'c, 'cc> {
         }
     }
 
+    #[allow(clippy::cast_possible_wrap)]
     fn constant_not(&self, o: &Constant, ty: ty::Ty<'_>) -> Option<Constant> {
         use self::Constant::*;
         match *o {
@@ -343,10 +344,10 @@ impl<'c, 'cc> ConstEvalLateContext<'c, 'cc> {
                             BinOpKind::Div if r != 0 => l.checked_div(r).map(zext),
                             BinOpKind::Rem if r != 0 => l.checked_rem(r).map(zext),
                             BinOpKind::Shr => l.checked_shr(
-                                    (r as u128).try_into().expect("shift too large")
+                                    r.try_into().expect("invalid shift")
                                 ).map(zext),
                             BinOpKind::Shl => l.checked_shl(
-                                    (r as u128).try_into().expect("shift too large")
+                                    r.try_into().expect("invalid shift")
                                 ).map(zext),
                             BinOpKind::BitXor => Some(zext(l ^ r)),
                             BinOpKind::BitOr => Some(zext(l | r)),

clippy_lints/src/enum_clike.rs

@@ -53,7 +53,7 @@ impl LintPass for UnportableVariant {
 }
 
 impl<'a, 'tcx> LateLintPass<'a, 'tcx> for UnportableVariant {
-    #[allow(clippy::cast_possible_truncation, clippy::cast_sign_loss)]
+    #[allow(clippy::cast_possible_truncation, clippy::cast_possible_wrap, clippy::cast_sign_loss)]
     fn check_item(&mut self, cx: &LateContext<'a, 'tcx>, item: &'tcx Item) {
         if cx.tcx.data_layout.pointer_size.bits() != 64 {
             return;

clippy_lints/src/utils/mod.rs

@@ -971,12 +971,14 @@ pub fn int_bits(tcx: TyCtxt<'_, '_, '_>, ity: ast::IntTy) -> u64 {
     layout::Integer::from_attr(tcx, attr::IntType::SignedInt(ity)).size().bits()
 }
 
+#[allow(clippy::cast_possible_wrap)]
 /// Turn a constant int byte representation into an i128
 pub fn sext(tcx: TyCtxt<'_, '_, '_>, u: u128, ity: ast::IntTy) -> i128 {
     let amt = 128 - int_bits(tcx, ity);
     ((u as i128) << amt) >> amt
 }
 
+#[allow(clippy::cast_sign_loss)]
 /// clip unused bytes
 pub fn unsext(tcx: TyCtxt<'_, '_, '_>, u: i128, ity: ast::IntTy) -> u128 {
     let amt = 128 - int_bits(tcx, ity);