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Add inline function get_slice_bytes to remove code duplication.

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This commit is contained in:
ben 2019-09-28 13:30:26 +12:00
parent 22b87a5515
commit 875fa72f9e
1 changed files with 17 additions and 23 deletions
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40
src/librustc/ty/relate.rs
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@ -584,32 +584,26 @@ pub fn super_relate_consts<R: TypeRelation<'tcx>>(
// FIXME(const_generics): we should either handle `Scalar::Ptr` or add a comment
// saying that we're not handling it intentionally.
(
ConstValue::Slice { data: alloc_a, start: offset_a, end: end_a },
ConstValue::Slice { data: alloc_b, start: offset_b, end: end_b },
) => {
let len_a = end_a - offset_a;
let len_b = end_b - offset_b;
let a_bytes = alloc_a
.get_bytes(
&tcx,
// invent a pointer, only the offset is relevant anyway
Pointer::new(AllocId(0), Size::from_bytes(offset_a as u64)),
Size::from_bytes(len_a as u64),
)
.unwrap_or_else(|err| bug!("const slice is invalid: {:?}", err));
(a_val @ ConstValue::Slice { .. }, b_val @ ConstValue::Slice { .. }) => {
fn get_slice_bytes<'tcx>(tcx: TyCtxt<'tcx>, val: ConstValue<'tcx>) -> &'tcx [u8] {
if let ConstValue::Slice { data, start, end } = val {
let len = end - start;
data.get_bytes(
&tcx,
// invent a pointer, only the offset is relevant anyway
Pointer::new(AllocId(0), Size::from_bytes(start as u64)),
Size::from_bytes(len as u64),
).unwrap_or_else(|err| bug!("const slice is invalid: {:?}", err))
} else {
unreachable!();
}
}
let b_bytes = alloc_b
.get_bytes(
&tcx,
// invent a pointer, only the offset is relevant anyway
Pointer::new(AllocId(0), Size::from_bytes(offset_b as u64)),
Size::from_bytes(len_b as u64),
)
.unwrap_or_else(|err| bug!("const slice is invalid: {:?}", err));
let a_bytes = get_slice_bytes(tcx, a_val);
let b_bytes = get_slice_bytes(tcx, b_val);
if a_bytes == b_bytes {
Ok(tcx.mk_const(ty::Const {
val: ConstValue::Slice { data: alloc_a, start: offset_a, end: end_a },
val: a_val,
ty: a.ty,
}))
} else {