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Malformed range patterns can't happen thanks to E0030

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This commit is contained in:
Nadrieril 2019-11-09 21:42:02 +00:00
parent 3e5aadc350
commit e47d631ca0
1 changed files with 6 additions and 8 deletions
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14
src/librustc_mir/hair/pattern/_match.rs
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@ -1118,8 +1118,7 @@ fn all_constructors<'a, 'tcx>(
debug!("all_constructors({:?})", pcx.ty);
let make_range = |start, end| {
IntRange(
// `unwrap()` is ok because we know the type is an integer and the range is
// well-formed.
// `unwrap()` is ok because we know the type is an integer.
IntRange::from_range(cx.tcx, start, end, pcx.ty, &RangeEnd::Included, pcx.span)
.unwrap(),
)
@ -1318,13 +1317,12 @@ impl<'tcx> IntRange<'tcx> {
// which makes the interval arithmetic simpler.
let bias = IntRange::signed_bias(tcx, ty);
let (lo, hi) = (lo ^ bias, hi ^ bias);
// Make sure the interval is well-formed.
if lo > hi || lo == hi && *end == RangeEnd::Excluded {
None
} else {
let offset = (*end == RangeEnd::Excluded) as u128;
Some(IntRange { range: lo..=(hi - offset), ty, span })
let offset = (*end == RangeEnd::Excluded) as u128;
if lo > hi || (lo == hi && *end == RangeEnd::Excluded) {
// This hould have been caught earlier by E0030
bug!("malformed range pattern: {}..={}", lo, (hi - offset));
}
Some(IntRange { range: lo..=(hi - offset), ty, span })
} else {
None
}