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Prefer IntRange::into_ctor to range_to_ctor

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This commit is contained in:
Nadrieril 2019-11-07 20:03:50 +00:00
parent 0a186103ae
commit 6de7afdf95
1 changed files with 34 additions and 47 deletions
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81
src/librustc_mir/hair/pattern/_match.rs
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@ -1389,20 +1389,15 @@ impl<'tcx> IntRange<'tcx> {
}
}
/// Converts a `RangeInclusive` to a `ConstantValue` or inclusive `ConstantRange`.
fn range_to_ctor(
tcx: TyCtxt<'tcx>,
ty: Ty<'tcx>,
r: RangeInclusive<u128>,
span: Span,
) -> Constructor<'tcx> {
let bias = IntRange::signed_bias(tcx, ty);
let (lo, hi) = r.into_inner();
/// Converts an `IntRange` to a `ConstantValue` or inclusive `ConstantRange`.
fn into_ctor(self, tcx: TyCtxt<'tcx>) -> Constructor<'tcx> {
let bias = IntRange::signed_bias(tcx, self.ty);
let (lo, hi) = self.range.into_inner();
if lo == hi {
let ty = ty::ParamEnv::empty().and(ty);
ConstantValue(ty::Const::from_bits(tcx, lo ^ bias, ty), span)
let ty = ty::ParamEnv::empty().and(self.ty);
ConstantValue(ty::Const::from_bits(tcx, lo ^ bias, ty), self.span)
} else {
ConstantRange(lo ^ bias, hi ^ bias, ty, RangeEnd::Included, span)
ConstantRange(lo ^ bias, hi ^ bias, self.ty, RangeEnd::Included, self.span)
}
}
@ -1419,38 +1414,27 @@ impl<'tcx> IntRange<'tcx> {
.filter_map(|r| IntRange::from_ctor(tcx, param_env, &r).map(|i| i.range));
let mut remaining_ranges = vec![];
let ty = self.ty;
let span = self.span;
let (lo, hi) = self.range.into_inner();
for subrange in ranges {
let (subrange_lo, subrange_hi) = subrange.into_inner();
if lo > subrange_hi || subrange_lo > hi {
// The pattern doesn't intersect with the subrange at all,
// so the subrange remains untouched.
remaining_ranges.push(Self::range_to_ctor(
tcx,
ty,
subrange_lo..=subrange_hi,
self.span,
));
remaining_ranges
.push(IntRange { range: subrange_lo..=subrange_hi, ty, span }.into_ctor(tcx));
} else {
if lo > subrange_lo {
// The pattern intersects an upper section of the
// subrange, so a lower section will remain.
remaining_ranges.push(Self::range_to_ctor(
tcx,
ty,
subrange_lo..=(lo - 1),
self.span,
));
remaining_ranges
.push(IntRange { range: subrange_lo..=(lo - 1), ty, span }.into_ctor(tcx));
}
if hi < subrange_hi {
// The pattern intersects a lower section of the
// subrange, so an upper section will remain.
remaining_ranges.push(Self::range_to_ctor(
tcx,
ty,
(hi + 1)..=subrange_hi,
self.span,
));
remaining_ranges
.push(IntRange { range: (hi + 1)..=subrange_hi, ty, span }.into_ctor(tcx));
}
}
}
@ -1964,23 +1948,24 @@ fn split_grouped_constructors<'p, 'tcx>(
// We're going to iterate through every adjacent pair of borders, making sure that
// each represents an interval of nonnegative length, and convert each such
// interval into a constructor.
for IntRange { range, .. } in
borders.windows(2).filter_map(|window| match (window[0], window[1]) {
(Border::JustBefore(n), Border::JustBefore(m)) => {
if n < m {
Some(IntRange { range: n..=(m - 1), ty, span })
} else {
None
split_ctors.extend(
borders
.windows(2)
.filter_map(|window| match (window[0], window[1]) {
(Border::JustBefore(n), Border::JustBefore(m)) => {
if n < m {
Some(IntRange { range: n..=(m - 1), ty, span })
} else {
None
}
}
}
(Border::JustBefore(n), Border::AfterMax) => {
Some(IntRange { range: n..=u128::MAX, ty, span })
}
(Border::AfterMax, _) => None,
})
{
split_ctors.push(IntRange::range_to_ctor(tcx, ty, range, span));
}
(Border::JustBefore(n), Border::AfterMax) => {
Some(IntRange { range: n..=u128::MAX, ty, span })
}
(Border::AfterMax, _) => None,
})
.map(|range| range.into_ctor(tcx)),
);
}
VarLenSlice(self_prefix, self_suffix) => {
// The exhaustiveness-checking paper does not include any details on
@ -2127,7 +2112,9 @@ fn lint_overlapping_patterns(
int_range.span,
&format!(
"this range overlaps on `{}`",
IntRange::range_to_ctor(tcx, ty, int_range.range, DUMMY_SP).display(tcx),
IntRange { range: int_range.range, ty, span: DUMMY_SP }
.into_ctor(tcx)
.display(tcx),
),
);
}