/// + If some constructors are missing from the matrix, it turns out we don't need to do
/// anything special (because we know none of the integers are actually wildcards: i.e., we
/// can't span wildcards using ranges).
-
use self::Constructor::*;
use self::Usefulness::*;
use self::WitnessPreference::*;
use rustc_data_structures::fx::FxHashMap;
use rustc_index::vec::Idx;
+use super::{compare_const_vals, PatternFoldable, PatternFolder};
use super::{FieldPat, Pat, PatKind, PatRange};
-use super::{PatternFoldable, PatternFolder, compare_const_vals};
use rustc::hir::def_id::DefId;
-use rustc::hir::{RangeEnd, HirId};
-use rustc::ty::{self, Ty, TyCtxt, TypeFoldable, Const};
-use rustc::ty::layout::{Integer, IntegerExt, VariantIdx, Size};
+use rustc::hir::{HirId, RangeEnd};
+use rustc::ty::layout::{Integer, IntegerExt, Size, VariantIdx};
+use rustc::ty::{self, Const, Ty, TyCtxt, TypeFoldable};
+use rustc::lint;
+use rustc::mir::interpret::{truncate, AllocId, ConstValue, Pointer, Scalar};
use rustc::mir::Field;
-use rustc::mir::interpret::{ConstValue, Scalar, truncate, AllocId, Pointer};
use rustc::util::common::ErrorReported;
-use rustc::lint;
use syntax::attr::{SignedInt, UnsignedInt};
use syntax_pos::{Span, DUMMY_SP};
use arena::TypedArena;
-use smallvec::{SmallVec, smallvec};
-use std::cmp::{self, Ordering, min, max};
+use smallvec::{smallvec, SmallVec};
+use std::cmp::{self, max, min, Ordering};
+use std::convert::TryInto;
use std::fmt;
use std::iter::{FromIterator, IntoIterator};
use std::ops::RangeInclusive;
use std::u128;
-use std::convert::TryInto;
pub fn expand_pattern<'a, 'tcx>(cx: &MatchCheckCtxt<'a, 'tcx>, pat: Pat<'tcx>) -> Pat<'tcx> {
LiteralExpander { tcx: cx.tcx }.fold_pattern(&pat)
// the easy case, deref a reference
(ConstValue::Scalar(Scalar::Ptr(p)), x, y) if x == y => {
let alloc = self.tcx.alloc_map.lock().unwrap_memory(p.alloc_id);
- ConstValue::ByRef {
- alloc,
- offset: p.offset,
- }
- },
+ ConstValue::ByRef { alloc, offset: p.offset }
+ }
// unsize array to slice if pattern is array but match value or other patterns are slice
(ConstValue::Scalar(Scalar::Ptr(p)), ty::Array(t, n), ty::Slice(u)) => {
assert_eq!(t, u);
start: p.offset.bytes().try_into().unwrap(),
end: n.eval_usize(self.tcx, ty::ParamEnv::empty()).try_into().unwrap(),
}
- },
+ }
// fat pointers stay the same
- | (ConstValue::Slice { .. }, _, _)
+ (ConstValue::Slice { .. }, _, _)
| (_, ty::Slice(_), ty::Slice(_))
- | (_, ty::Str, ty::Str)
- => val,
+ | (_, ty::Str, ty::Str) => val,
// FIXME(oli-obk): this is reachable for `const FOO: &&&u32 = &&&42;` being used
_ => bug!("cannot deref {:#?}, {} -> {}", val, crty, rty),
}
match (&pat.ty.kind, &*pat.kind) {
(
&ty::Ref(_, rty, _),
- &PatKind::Constant { value: Const {
- val,
- ty: ty::TyS { kind: ty::Ref(_, crty, _), .. },
- } },
- ) => {
- Pat {
- ty: pat.ty,
- span: pat.span,
- kind: box PatKind::Deref {
- subpattern: Pat {
- ty: rty,
- span: pat.span,
- kind: box PatKind::Constant { value: self.tcx.mk_const(Const {
+ &PatKind::Constant {
+ value: Const { val, ty: ty::TyS { kind: ty::Ref(_, crty, _), .. } },
+ },
+ ) => Pat {
+ ty: pat.ty,
+ span: pat.span,
+ kind: box PatKind::Deref {
+ subpattern: Pat {
+ ty: rty,
+ span: pat.span,
+ kind: box PatKind::Constant {
+ value: self.tcx.mk_const(Const {
val: self.fold_const_value_deref(*val, rty, crty),
ty: rty,
- }) },
- }
- }
- }
- }
- (_, &PatKind::Binding { subpattern: Some(ref s), .. }) => {
- s.fold_with(self)
- }
- _ => pat.super_fold_with(self)
+ }),
+ },
+ },
+ },
+ },
+ (_, &PatKind::Binding { subpattern: Some(ref s), .. }) => s.fold_with(self),
+ _ => pat.super_fold_with(self),
}
}
}
impl<'tcx> Pat<'tcx> {
fn is_wildcard(&self) -> bool {
match *self.kind {
- PatKind::Binding { subpattern: None, .. } | PatKind::Wild =>
- true,
- _ => false
+ PatKind::Binding { subpattern: None, .. } | PatKind::Wild => true,
+ _ => false,
}
}
}
write!(f, "\n")?;
let &Matrix(ref m) = self;
- let pretty_printed_matrix: Vec<Vec<String>> = m.iter().map(|row| {
- row.iter().map(|pat| format!("{:?}", pat)).collect()
- }).collect();
+ let pretty_printed_matrix: Vec<Vec<String>> =
+ m.iter().map(|row| row.iter().map(|pat| format!("{:?}", pat)).collect()).collect();
let column_count = m.iter().map(|row| row.len()).max().unwrap_or(0);
assert!(m.iter().all(|row| row.len() == column_count));
- let column_widths: Vec<usize> = (0..column_count).map(|col| {
- pretty_printed_matrix.iter().map(|row| row[col].len()).max().unwrap_or(0)
- }).collect();
+ let column_widths: Vec<usize> = (0..column_count)
+ .map(|col| pretty_printed_matrix.iter().map(|row| row[col].len()).max().unwrap_or(0))
+ .collect();
let total_width = column_widths.iter().cloned().sum::<usize>() + column_count * 3 + 1;
let br = "+".repeat(total_width);
impl<'p, 'tcx> FromIterator<SmallVec<[&'p Pat<'tcx>; 2]>> for Matrix<'p, 'tcx> {
fn from_iter<T>(iter: T) -> Self
- where T: IntoIterator<Item=SmallVec<[&'p Pat<'tcx>; 2]>>
+ where
+ T: IntoIterator<Item = SmallVec<[&'p Pat<'tcx>; 2]>>,
{
Matrix(iter.into_iter().collect())
}
VariantIdx::new(0)
}
ConstantValue(c, _) => crate::const_eval::const_variant_index(cx.tcx, cx.param_env, c),
- _ => bug!("bad constructor {:?} for adt {:?}", self, adt)
+ _ => bug!("bad constructor {:?} for adt {:?}", self, adt),
}
}
pub enum Usefulness<'tcx> {
Useful,
UsefulWithWitness(Vec<Witness<'tcx>>),
- NotUseful
+ NotUseful,
}
impl<'tcx> Usefulness<'tcx> {
fn is_useful(&self) -> bool {
match *self {
NotUseful => false,
- _ => true
+ _ => true,
}
}
}
#[derive(Copy, Clone, Debug)]
pub enum WitnessPreference {
ConstructWitness,
- LeaveOutWitness
+ LeaveOutWitness,
}
#[derive(Copy, Clone, Debug)]
mut self,
cx: &MatchCheckCtxt<'a, 'tcx>,
ctor: &Constructor<'tcx>,
- ty: Ty<'tcx>)
- -> Self
- {
+ ty: Ty<'tcx>,
+ ) -> Self {
let sub_pattern_tys = constructor_sub_pattern_tys(cx, ctor, ty);
- self.0.extend(sub_pattern_tys.into_iter().map(|ty| {
- Pat {
- ty,
- span: DUMMY_SP,
- kind: box PatKind::Wild,
- }
+ self.0.extend(sub_pattern_tys.into_iter().map(|ty| Pat {
+ ty,
+ span: DUMMY_SP,
+ kind: box PatKind::Wild,
}));
self.apply_constructor(cx, ctor, ty)
}
/// pats: [(false, "foo"), 42] => X { a: (false, "foo"), b: 42 }
fn apply_constructor<'a>(
mut self,
- cx: &MatchCheckCtxt<'a,'tcx>,
+ cx: &MatchCheckCtxt<'a, 'tcx>,
ctor: &Constructor<'tcx>,
- ty: Ty<'tcx>)
- -> Self
- {
+ ty: Ty<'tcx>,
+ ) -> Self {
let arity = constructor_arity(cx, ctor, ty);
let pat = {
let len = self.0.len() as u64;
let mut pats = self.0.drain((len - arity) as usize..).rev();
match ty.kind {
- ty::Adt(..) |
- ty::Tuple(..) => {
- let pats = pats.enumerate().map(|(i, p)| {
- FieldPat {
- field: Field::new(i),
- pattern: p
- }
- }).collect();
+ ty::Adt(..) | ty::Tuple(..) => {
+ let pats = pats
+ .enumerate()
+ .map(|(i, p)| FieldPat { field: Field::new(i), pattern: p })
+ .collect();
if let ty::Adt(adt, substs) = ty.kind {
if adt.is_enum() {
adt_def: adt,
substs,
variant_index: ctor.variant_index_for_adt(cx, adt),
- subpatterns: pats
+ subpatterns: pats,
}
} else {
PatKind::Leaf { subpatterns: pats }
}
}
- ty::Ref(..) => {
- PatKind::Deref { subpattern: pats.nth(0).unwrap() }
- }
+ ty::Ref(..) => PatKind::Deref { subpattern: pats.nth(0).unwrap() },
ty::Slice(_) | ty::Array(..) => {
- PatKind::Slice {
- prefix: pats.collect(),
- slice: None,
- suffix: vec![]
- }
+ PatKind::Slice { prefix: pats.collect(), slice: None, suffix: vec![] }
}
- _ => {
- match *ctor {
- ConstantValue(value, _) => PatKind::Constant { value },
- ConstantRange(lo, hi, ty, end, _) => PatKind::Range(PatRange {
- lo: ty::Const::from_bits(cx.tcx, lo, ty::ParamEnv::empty().and(ty)),
- hi: ty::Const::from_bits(cx.tcx, hi, ty::ParamEnv::empty().and(ty)),
- end,
- }),
- _ => PatKind::Wild,
- }
- }
+ _ => match *ctor {
+ ConstantValue(value, _) => PatKind::Constant { value },
+ ConstantRange(lo, hi, ty, end, _) => PatKind::Range(PatRange {
+ lo: ty::Const::from_bits(cx.tcx, lo, ty::ParamEnv::empty().and(ty)),
+ hi: ty::Const::from_bits(cx.tcx, hi, ty::ParamEnv::empty().and(ty)),
+ end,
+ }),
+ _ => PatKind::Wild,
+ },
}
};
- self.0.push(Pat {
- ty,
- span: DUMMY_SP,
- kind: Box::new(pat),
- });
+ self.0.push(Pat { ty, span: DUMMY_SP, kind: Box::new(pat) });
self
}
) -> Vec<Constructor<'tcx>> {
debug!("all_constructors({:?})", pcx.ty);
let ctors = match pcx.ty.kind {
- ty::Bool => {
- [true, false].iter().map(|&b| {
- ConstantValue(ty::Const::from_bool(cx.tcx, b), pcx.span)
- }).collect()
- }
+ ty::Bool => [true, false]
+ .iter()
+ .map(|&b| ConstantValue(ty::Const::from_bool(cx.tcx, b), pcx.span))
+ .collect(),
ty::Array(ref sub_ty, len) if len.try_eval_usize(cx.tcx, cx.param_env).is_some() => {
let len = len.eval_usize(cx.tcx, cx.param_env);
- if len != 0 && cx.is_uninhabited(sub_ty) {
- vec![]
- } else {
- vec![Slice(len)]
- }
+ if len != 0 && cx.is_uninhabited(sub_ty) { vec![] } else { vec![Slice(len)] }
}
// Treat arrays of a constant but unknown length like slices.
- ty::Array(ref sub_ty, _) |
- ty::Slice(ref sub_ty) => {
+ ty::Array(ref sub_ty, _) | ty::Slice(ref sub_ty) => {
if cx.is_uninhabited(sub_ty) {
vec![Slice(0)]
} else {
- (0..pcx.max_slice_length+1).map(|length| Slice(length)).collect()
+ (0..pcx.max_slice_length + 1).map(|length| Slice(length)).collect()
}
}
- ty::Adt(def, substs) if def.is_enum() => {
- def.variants.iter()
- .filter(|v| {
- !cx.tcx.features().exhaustive_patterns ||
- !v.uninhabited_from(cx.tcx, substs, def.adt_kind()).contains(cx.tcx, cx.module)
- })
- .map(|v| Variant(v.def_id))
- .collect()
- }
+ ty::Adt(def, substs) if def.is_enum() => def
+ .variants
+ .iter()
+ .filter(|v| {
+ !cx.tcx.features().exhaustive_patterns
+ || !v
+ .uninhabited_from(cx.tcx, substs, def.adt_kind())
+ .contains(cx.tcx, cx.module)
+ })
+ .map(|v| Variant(v.def_id))
+ .collect(),
ty::Char => {
vec![
// The valid Unicode Scalar Value ranges.
PatKind::Constant { value } => {
// extract the length of an array/slice from a constant
match (value.val, &value.ty.kind) {
- (_, ty::Array(_, n)) => max_fixed_len = cmp::max(
- max_fixed_len,
- n.eval_usize(cx.tcx, cx.param_env),
- ),
- (ConstValue::Slice{ start, end, .. }, ty::Slice(_)) => max_fixed_len = cmp::max(
- max_fixed_len,
- (end - start) as u64,
- ),
- _ => {},
+ (_, ty::Array(_, n)) => {
+ max_fixed_len = cmp::max(max_fixed_len, n.eval_usize(cx.tcx, cx.param_env))
+ }
+ (ConstValue::Slice { start, end, .. }, ty::Slice(_)) => {
+ max_fixed_len = cmp::max(max_fixed_len, (end - start) as u64)
+ }
+ _ => {}
}
}
PatKind::Slice { ref prefix, slice: None, ref suffix } => {
// This is a more general form of the previous branch.
val
} else {
- return None
+ return None;
};
let val = val ^ bias;
Some(IntRange { range: val..=val, ty, span })
}
box PatKind::AscribeUserType { ref subpattern, .. } => {
pat = subpattern;
- },
+ }
_ => return None,
}
}
let bits = Integer::from_attr(&tcx, SignedInt(ity)).size().bits() as u128;
1u128 << (bits - 1)
}
- _ => 0
+ _ => 0,
}
}
param_env: ty::ParamEnv<'tcx>,
ranges: Vec<Constructor<'tcx>>,
) -> Vec<Constructor<'tcx>> {
- let ranges = ranges.into_iter().filter_map(|r| {
- IntRange::from_ctor(tcx, param_env, &r).map(|i| i.range)
- });
+ let ranges = ranges
+ .into_iter()
+ .filter_map(|r| IntRange::from_ctor(tcx, param_env, &r).map(|i| i.range));
let mut remaining_ranges = vec![];
let ty = self.ty;
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 {
+ 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(Self::range_to_ctor(
+ tcx,
+ ty,
+ subrange_lo..=subrange_hi,
+ self.span,
+ ));
} 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(Self::range_to_ctor(
+ tcx,
+ ty,
+ subrange_lo..=(lo - 1),
+ self.span,
+ ));
}
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(Self::range_to_ctor(
+ tcx,
+ ty,
+ (hi + 1)..=subrange_hi,
+ self.span,
+ ));
}
}
}
}
} else {
NotUseful
- }
+ };
};
assert!(rows.iter().all(|r| r.len() == v.len()));
- let (ty, span) = rows.iter()
+ let (ty, span) = rows
+ .iter()
.map(|r| (r[0].ty, r[0].span))
.find(|(ty, _)| !ty.references_error())
.unwrap_or((v[0].ty, v[0].span));
if let Some(constructors) = pat_constructors(cx, v[0], pcx) {
debug!("is_useful - expanding constructors: {:#?}", constructors);
split_grouped_constructors(
- cx.tcx, cx.param_env, constructors, matrix, pcx.ty, pcx.span, Some(hir_id),
- ).into_iter().map(|c|
- is_useful_specialized(cx, matrix, v, c, pcx.ty, witness, hir_id)
- ).find(|result| result.is_useful()).unwrap_or(NotUseful)
+ cx.tcx,
+ cx.param_env,
+ constructors,
+ matrix,
+ pcx.ty,
+ pcx.span,
+ Some(hir_id),
+ )
+ .into_iter()
+ .map(|c| is_useful_specialized(cx, matrix, v, c, pcx.ty, witness, hir_id))
+ .find(|result| result.is_useful())
+ .unwrap_or(NotUseful)
} else {
debug!("is_useful - expanding wildcard");
- let used_ctors: Vec<Constructor<'_>> = rows.iter().flat_map(|row| {
- pat_constructors(cx, row[0], pcx).unwrap_or(vec![])
- }).collect();
+ let used_ctors: Vec<Constructor<'_>> = rows
+ .iter()
+ .flat_map(|row| pat_constructors(cx, row[0], pcx).unwrap_or(vec![]))
+ .collect();
debug!("used_ctors = {:#?}", used_ctors);
// `all_ctors` are all the constructors for the given type, which
// should all be represented (or caught with the wild pattern `_`).
// the set is empty, but we only fully construct them on-demand,
// because they're rarely used and can be big.
let cheap_missing_ctors = compute_missing_ctors(
- MissingCtorsInfo::Emptiness, cx.tcx, cx.param_env, &all_ctors, &used_ctors,
+ MissingCtorsInfo::Emptiness,
+ cx.tcx,
+ cx.param_env,
+ &all_ctors,
+ &used_ctors,
);
let is_privately_empty = all_ctors.is_empty() && !cx.is_uninhabited(pcx.ty);
let is_declared_nonexhaustive = cx.is_non_exhaustive_enum(pcx.ty) && !cx.is_local(pcx.ty);
- debug!("cheap_missing_ctors={:#?} is_privately_empty={:#?} is_declared_nonexhaustive={:#?}",
- cheap_missing_ctors, is_privately_empty, is_declared_nonexhaustive);
+ debug!(
+ "cheap_missing_ctors={:#?} is_privately_empty={:#?} is_declared_nonexhaustive={:#?}",
+ cheap_missing_ctors, is_privately_empty, is_declared_nonexhaustive
+ );
// For privately empty and non-exhaustive enums, we work as if there were an "extra"
// `_` constructor for the type, so we can never match over all constructors.
- let is_non_exhaustive = is_privately_empty || is_declared_nonexhaustive ||
- (pcx.ty.is_ptr_sized_integral() && !cx.tcx.features().precise_pointer_size_matching);
+ let is_non_exhaustive = is_privately_empty
+ || is_declared_nonexhaustive
+ || (pcx.ty.is_ptr_sized_integral() && !cx.tcx.features().precise_pointer_size_matching);
if cheap_missing_ctors == MissingCtors::Empty && !is_non_exhaustive {
split_grouped_constructors(
- cx.tcx, cx.param_env, all_ctors, matrix, pcx.ty, DUMMY_SP, None,
+ cx.tcx,
+ cx.param_env,
+ all_ctors,
+ matrix,
+ pcx.ty,
+ DUMMY_SP,
+ None,
)
- .into_iter()
- .map(|c| is_useful_specialized(cx, matrix, v, c, pcx.ty, witness, hir_id))
- .find(|result| result.is_useful())
- .unwrap_or(NotUseful)
+ .into_iter()
+ .map(|c| is_useful_specialized(cx, matrix, v, c, pcx.ty, witness, hir_id))
+ .find(|result| result.is_useful())
+ .unwrap_or(NotUseful)
} else {
- let matrix = rows.iter().filter_map(|r| {
- if r[0].is_wildcard() {
- Some(SmallVec::from_slice(&r[1..]))
- } else {
- None
- }
- }).collect();
+ let matrix = rows
+ .iter()
+ .filter_map(|r| {
+ if r[0].is_wildcard() { Some(SmallVec::from_slice(&r[1..])) } else { None }
+ })
+ .collect();
match is_useful(cx, &matrix, &v[1..], witness, hir_id) {
UsefulWithWitness(pats) => {
let cx = &*cx;
let new_witnesses = if is_non_exhaustive || used_ctors.is_empty() {
// All constructors are unused. Add wild patterns
// rather than each individual constructor.
- pats.into_iter().map(|mut witness| {
- witness.0.push(Pat {
- ty: pcx.ty,
- span: DUMMY_SP,
- kind: box PatKind::Wild,
- });
- witness
- }).collect()
+ pats.into_iter()
+ .map(|mut witness| {
+ witness.0.push(Pat {
+ ty: pcx.ty,
+ span: DUMMY_SP,
+ kind: box PatKind::Wild,
+ });
+ witness
+ })
+ .collect()
} else {
let expensive_missing_ctors = compute_missing_ctors(
- MissingCtorsInfo::Ctors, cx.tcx, cx.param_env, &all_ctors, &used_ctors,
+ MissingCtorsInfo::Ctors,
+ cx.tcx,
+ cx.param_env,
+ &all_ctors,
+ &used_ctors,
);
if let MissingCtors::Ctors(missing_ctors) = expensive_missing_ctors {
- pats.into_iter().flat_map(|witness| {
- missing_ctors.iter().map(move |ctor| {
- // Extends the witness with a "wild" version of this
- // constructor, that matches everything that can be built with
- // it. For example, if `ctor` is a `Constructor::Variant` for
- // `Option::Some`, this pushes the witness for `Some(_)`.
- witness.clone().push_wild_constructor(cx, ctor, pcx.ty)
+ pats.into_iter()
+ .flat_map(|witness| {
+ missing_ctors.iter().map(move |ctor| {
+ // Extends the witness with a "wild" version of this
+ // constructor, that matches everything that can be built with
+ // it. For example, if `ctor` is a `Constructor::Variant` for
+ // `Option::Some`, this pushes the witness for `Some(_)`.
+ witness.clone().push_wild_constructor(cx, ctor, pcx.ty)
+ })
})
- }).collect()
+ .collect()
} else {
bug!("cheap missing ctors")
}
};
UsefulWithWitness(new_witnesses)
}
- result => result
+ result => result,
}
}
}
) -> Usefulness<'tcx> {
debug!("is_useful_specialized({:#?}, {:#?}, {:?})", v, ctor, lty);
let sub_pat_tys = constructor_sub_pattern_tys(cx, &ctor, lty);
- let wild_patterns_owned: Vec<_> = sub_pat_tys.iter().map(|ty| {
- Pat {
- ty,
- span: DUMMY_SP,
- kind: box PatKind::Wild,
- }
- }).collect();
+ let wild_patterns_owned: Vec<_> =
+ sub_pat_tys.iter().map(|ty| Pat { ty, span: DUMMY_SP, kind: box PatKind::Wild }).collect();
let wild_patterns: Vec<_> = wild_patterns_owned.iter().collect();
- let matrix = Matrix(
- m.iter()
- .filter_map(|r| specialize(cx, &r, &ctor, &wild_patterns))
- .collect()
- );
+ let matrix =
+ Matrix(m.iter().filter_map(|r| specialize(cx, &r, &ctor, &wild_patterns)).collect());
match specialize(cx, v, &ctor, &wild_patterns) {
Some(v) => match is_useful(cx, &matrix, &v, witness, hir_id) {
UsefulWithWitness(witnesses) => UsefulWithWitness(
- witnesses.into_iter()
+ witnesses
+ .into_iter()
.map(|witness| witness.apply_constructor(cx, &ctor, lty))
- .collect()
+ .collect(),
),
- result => result
- }
- None => NotUseful
+ result => result,
+ },
+ None => NotUseful,
}
}
pcx: PatCtxt<'tcx>,
) -> Option<Vec<Constructor<'tcx>>> {
match *pat.kind {
- PatKind::AscribeUserType { ref subpattern, .. } =>
- pat_constructors(cx, subpattern, pcx),
+ PatKind::AscribeUserType { ref subpattern, .. } => pat_constructors(cx, subpattern, pcx),
PatKind::Binding { .. } | PatKind::Wild => None,
PatKind::Leaf { .. } | PatKind::Deref { .. } => Some(vec![Single]),
PatKind::Variant { adt_def, variant_index, .. } => {
Some(vec![Variant(adt_def.variants[variant_index].def_id)])
}
PatKind::Constant { value } => Some(vec![ConstantValue(value, pat.span)]),
- PatKind::Range(PatRange { lo, hi, end }) =>
- Some(vec![ConstantRange(
- lo.eval_bits(cx.tcx, cx.param_env, lo.ty),
- hi.eval_bits(cx.tcx, cx.param_env, hi.ty),
- lo.ty,
- end,
- pat.span,
- )]),
+ PatKind::Range(PatRange { lo, hi, end }) => Some(vec![ConstantRange(
+ lo.eval_bits(cx.tcx, cx.param_env, lo.ty),
+ hi.eval_bits(cx.tcx, cx.param_env, hi.ty),
+ lo.ty,
+ end,
+ pat.span,
+ )]),
PatKind::Array { .. } => match pcx.ty.kind {
- ty::Array(_, length) => Some(vec![
- Slice(length.eval_usize(cx.tcx, cx.param_env))
- ]),
- _ => span_bug!(pat.span, "bad ty {:?} for array pattern", pcx.ty)
+ ty::Array(_, length) => Some(vec![Slice(length.eval_usize(cx.tcx, cx.param_env))]),
+ _ => span_bug!(pat.span, "bad ty {:?} for array pattern", pcx.ty),
},
PatKind::Slice { ref prefix, ref slice, ref suffix } => {
let pat_len = prefix.len() as u64 + suffix.len() as u64;
if slice.is_some() {
- Some((pat_len..pcx.max_slice_length+1).map(Slice).collect())
+ Some((pat_len..pcx.max_slice_length + 1).map(Slice).collect())
} else {
Some(vec![Slice(pat_len)])
}
ty::Slice(..) | ty::Array(..) => match *ctor {
Slice(length) => length,
ConstantValue(..) => 0,
- _ => bug!("bad slice pattern {:?} {:?}", ctor, ty)
- }
+ _ => bug!("bad slice pattern {:?} {:?}", ctor, ty),
+ },
ty::Ref(..) => 1,
- ty::Adt(adt, _) => {
- adt.variants[ctor.variant_index_for_adt(cx, adt)].fields.len() as u64
- }
- _ => 0
+ ty::Adt(adt, _) => adt.variants[ctor.variant_index_for_adt(cx, adt)].fields.len() as u64,
+ _ => 0,
}
}
ty::Slice(ty) | ty::Array(ty, _) => match *ctor {
Slice(length) => (0..length).map(|_| ty).collect(),
ConstantValue(..) => vec![],
- _ => bug!("bad slice pattern {:?} {:?}", ctor, ty)
- }
+ _ => bug!("bad slice pattern {:?} {:?}", ctor, ty),
+ },
ty::Ref(_, rty, _) => vec![rty],
ty::Adt(adt, substs) => {
if adt.is_box() {
} else {
let variant = &adt.variants[ctor.variant_index_for_adt(cx, adt)];
let is_non_exhaustive = variant.is_field_list_non_exhaustive() && !cx.is_local(ty);
- variant.fields.iter().map(|field| {
- let is_visible = adt.is_enum()
- || field.vis.is_accessible_from(cx.module, cx.tcx);
- let is_uninhabited = cx.is_uninhabited(field.ty(cx.tcx, substs));
- match (is_visible, is_non_exhaustive, is_uninhabited) {
- // Treat all uninhabited types in non-exhaustive variants as `TyErr`.
- (_, true, true) => cx.tcx.types.err,
- // Treat all non-visible fields as `TyErr`. They can't appear in any
- // other pattern from this match (because they are private), so their
- // type does not matter - but we don't want to know they are uninhabited.
- (false, ..) => cx.tcx.types.err,
- (true, ..) => {
- let ty = field.ty(cx.tcx, substs);
- match ty.kind {
- // If the field type returned is an array of an unknown
- // size return an TyErr.
- ty::Array(_, len)
- if len.try_eval_usize(cx.tcx, cx.param_env).is_none() =>
- cx.tcx.types.err,
- _ => ty,
+ variant
+ .fields
+ .iter()
+ .map(|field| {
+ let is_visible =
+ adt.is_enum() || field.vis.is_accessible_from(cx.module, cx.tcx);
+ let is_uninhabited = cx.is_uninhabited(field.ty(cx.tcx, substs));
+ match (is_visible, is_non_exhaustive, is_uninhabited) {
+ // Treat all uninhabited types in non-exhaustive variants as `TyErr`.
+ (_, true, true) => cx.tcx.types.err,
+ // Treat all non-visible fields as `TyErr`. They can't appear in any
+ // other pattern from this match (because they are private), so their
+ // type does not matter - but we don't want to know they are uninhabited.
+ (false, ..) => cx.tcx.types.err,
+ (true, ..) => {
+ let ty = field.ty(cx.tcx, substs);
+ match ty.kind {
+ // If the field type returned is an array of an unknown
+ // size return an TyErr.
+ ty::Array(_, len)
+ if len.try_eval_usize(cx.tcx, cx.param_env).is_none() =>
+ {
+ cx.tcx.types.err
+ }
+ _ => ty,
+ }
}
- },
- }
- }).collect()
+ }
+ })
+ .collect()
}
}
_ => vec![],
let n = n.eval_usize(tcx, param_env);
let ptr = Pointer::new(AllocId(0), offset);
alloc.get_bytes(&tcx, ptr, Size::from_bytes(n)).unwrap()
- },
+ }
(ConstValue::Slice { data, start, end }, ty::Slice(t)) => {
assert_eq!(*t, tcx.types.u8);
let ptr = Pointer::new(AllocId(0), Size::from_bytes(start as u64));
data.get_bytes(&tcx, ptr, Size::from_bytes((end - start) as u64)).unwrap()
- },
+ }
// FIXME(oli-obk): create a way to extract fat pointers from ByRef
(_, ty::Slice(_)) => return Ok(false),
_ => bug!(
"slice_pat_covered_by_const: {:#?}, {:#?}, {:#?}, {:#?}",
- const_val, prefix, slice, suffix,
+ const_val,
+ prefix,
+ slice,
+ suffix,
),
};
return Ok(false);
}
- for (ch, pat) in
- data[..prefix.len()].iter().zip(prefix).chain(
- data[data.len()-suffix.len()..].iter().zip(suffix))
+ for (ch, pat) in data[..prefix.len()]
+ .iter()
+ .zip(prefix)
+ .chain(data[data.len() - suffix.len()..].iter().zip(suffix))
{
match pat.kind {
box PatKind::Constant { value } => {
let mut overlaps = vec![];
// `borders` is the set of borders between equivalence classes: each equivalence
// class lies between 2 borders.
- let row_borders = m.iter()
+ let row_borders = m
+ .iter()
.flat_map(|row| {
IntRange::from_pat(tcx, param_env, row[0]).map(|r| (r, row.len()))
})
// We're going to iterate through every 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]) {
+ 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 })
Some(IntRange { range: n..=u128::MAX, ty, span })
}
(Border::AfterMax, _) => None,
- }
- }) {
+ })
+ {
split_ctors.push(IntRange::range_to_ctor(tcx, ty, range, span));
}
}
err.span_label(ctor_range.span, "overlapping patterns");
for int_range in overlaps {
// Use the real type for user display of the ranges:
- err.span_label(int_range.span, &format!(
- "this range overlaps on `{}`",
- IntRange::range_to_ctor(tcx, ty, int_range.range, DUMMY_SP).display(tcx),
- ));
+ err.span_label(
+ int_range.span,
+ &format!(
+ "this range overlaps on `{}`",
+ IntRange::range_to_ctor(tcx, ty, int_range.range, DUMMY_SP).display(tcx),
+ ),
+ );
}
err.emit();
}
_ => bug!("`constructor_covered_by_range` called with {:?}", pat),
};
trace!("constructor_covered_by_range {:#?}, {:#?}, {:#?}, {}", ctor, from, to, ty);
- let cmp_from = |c_from| compare_const_vals(tcx, c_from, from, param_env, ty)
- .map(|res| res != Ordering::Less);
+ let cmp_from = |c_from| {
+ compare_const_vals(tcx, c_from, from, param_env, ty).map(|res| res != Ordering::Less)
+ };
let cmp_to = |c_to| compare_const_vals(tcx, c_to, to, param_env, ty);
macro_rules! some_or_ok {
($e:expr) => {
match *ctor {
ConstantValue(value, _) => {
let to = some_or_ok!(cmp_to(value));
- let end = (to == Ordering::Less) ||
- (end == RangeEnd::Included && to == Ordering::Equal);
+ let end =
+ (to == Ordering::Less) || (end == RangeEnd::Included && to == Ordering::Equal);
Ok(some_or_ok!(cmp_from(value)) && end)
- },
+ }
ConstantRange(from, to, ty, RangeEnd::Included, _) => {
- let to = some_or_ok!(cmp_to(ty::Const::from_bits(
- tcx,
- to,
- ty::ParamEnv::empty().and(ty),
- )));
- let end = (to == Ordering::Less) ||
- (end == RangeEnd::Included && to == Ordering::Equal);
+ let to =
+ some_or_ok!(cmp_to(ty::Const::from_bits(tcx, to, ty::ParamEnv::empty().and(ty),)));
+ let end =
+ (to == Ordering::Less) || (end == RangeEnd::Included && to == Ordering::Equal);
Ok(some_or_ok!(cmp_from(ty::Const::from_bits(
tcx,
from,
ty::ParamEnv::empty().and(ty),
))) && end)
- },
+ }
ConstantRange(from, to, ty, RangeEnd::Excluded, _) => {
- let to = some_or_ok!(cmp_to(ty::Const::from_bits(
- tcx,
- to,
- ty::ParamEnv::empty().and(ty)
- )));
- let end = (to == Ordering::Less) ||
- (end == RangeEnd::Excluded && to == Ordering::Equal);
+ let to =
+ some_or_ok!(cmp_to(ty::Const::from_bits(tcx, to, ty::ParamEnv::empty().and(ty))));
+ let end =
+ (to == Ordering::Less) || (end == RangeEnd::Excluded && to == Ordering::Equal);
Ok(some_or_ok!(cmp_from(ty::Const::from_bits(
tcx,
from,
- ty::ParamEnv::empty().and(ty)))
- ) && end)
+ ty::ParamEnv::empty().and(ty)
+ ))) && end)
}
Single => Ok(true),
_ => bug!(),
specialize(cx, ::std::slice::from_ref(&subpattern), constructor, wild_patterns)
}
- PatKind::Binding { .. } | PatKind::Wild => {
- Some(SmallVec::from_slice(wild_patterns))
- }
+ PatKind::Binding { .. } | PatKind::Wild => Some(SmallVec::from_slice(wild_patterns)),
PatKind::Variant { adt_def, variant_index, ref subpatterns, .. } => {
let ref variant = adt_def.variants[variant_index];
Some(patterns_for_variant(cx, subpatterns, wild_patterns, false))
}
- PatKind::Deref { ref subpattern } => {
- Some(smallvec![subpattern])
- }
+ PatKind::Deref { ref subpattern } => Some(smallvec![subpattern]),
PatKind::Constant { value } if constructor.is_slice() => {
// We extract an `Option` for the pointer because slices of zero
// just integers. The only time they should be pointing to memory
// is when they are subslices of nonzero slices.
let (alloc, offset, n, ty) = match value.ty.kind {
- ty::Array(t, n) => {
- match value.val {
- ConstValue::ByRef { offset, alloc, .. } => (
- alloc,
- offset,
- n.eval_usize(cx.tcx, cx.param_env),
- t,
- ),
- _ => span_bug!(
- pat.span,
- "array pattern is {:?}", value,
- ),
+ ty::Array(t, n) => match value.val {
+ ConstValue::ByRef { offset, alloc, .. } => {
+ (alloc, offset, n.eval_usize(cx.tcx, cx.param_env), t)
}
+ _ => span_bug!(pat.span, "array pattern is {:?}", value,),
},
ty::Slice(t) => {
match value.val {
- ConstValue::Slice { data, start, end } => (
- data,
- Size::from_bytes(start as u64),
- (end - start) as u64,
- t,
- ),
+ ConstValue::Slice { data, start, end } => {
+ (data, Size::from_bytes(start as u64), (end - start) as u64, t)
+ }
ConstValue::ByRef { .. } => {
// FIXME(oli-obk): implement `deref` for `ConstValue`
return None;
- },
+ }
_ => span_bug!(
pat.span,
"slice pattern constant must be scalar pair but is {:?}",
value,
),
}
- },
+ }
_ => span_bug!(
pat.span,
"unexpected const-val {:?} with ctor {:?}",
// convert a constant slice/array pattern to a list of patterns.
let layout = cx.tcx.layout_of(cx.param_env.and(ty)).ok()?;
let ptr = Pointer::new(AllocId(0), offset);
- (0..n).map(|i| {
- let ptr = ptr.offset(layout.size * i, &cx.tcx).ok()?;
- let scalar = alloc.read_scalar(
- &cx.tcx, ptr, layout.size,
- ).ok()?;
- let scalar = scalar.not_undef().ok()?;
- let value = ty::Const::from_scalar(cx.tcx, scalar, ty);
- let pattern = Pat {
- ty,
- span: pat.span,
- kind: box PatKind::Constant { value },
- };
- Some(&*cx.pattern_arena.alloc(pattern))
- }).collect()
+ (0..n)
+ .map(|i| {
+ let ptr = ptr.offset(layout.size * i, &cx.tcx).ok()?;
+ let scalar = alloc.read_scalar(&cx.tcx, ptr, layout.size).ok()?;
+ let scalar = scalar.not_undef().ok()?;
+ let value = ty::Const::from_scalar(cx.tcx, scalar, ty);
+ let pattern =
+ Pat { ty, span: pat.span, kind: box PatKind::Constant { value } };
+ Some(&*cx.pattern_arena.alloc(pattern))
+ })
+ .collect()
} else {
None
}
}
- PatKind::Constant { .. } |
- PatKind::Range { .. } => {
+ PatKind::Constant { .. } | PatKind::Range { .. } => {
// If the constructor is a:
// - Single value: add a row if the pattern contains the constructor.
// - Range: add a row if the constructor intersects the pattern.
if should_treat_range_exhaustively(cx.tcx, constructor) {
- match (IntRange::from_ctor(cx.tcx, cx.param_env, constructor),
- IntRange::from_pat(cx.tcx, cx.param_env, pat)) {
- (Some(ctor), Some(pat)) => {
- ctor.intersection(&pat).map(|_| {
- let (pat_lo, pat_hi) = pat.range.into_inner();
- let (ctor_lo, ctor_hi) = ctor.range.into_inner();
- assert!(pat_lo <= ctor_lo && ctor_hi <= pat_hi);
- smallvec![]
- })
- }
+ match (
+ IntRange::from_ctor(cx.tcx, cx.param_env, constructor),
+ IntRange::from_pat(cx.tcx, cx.param_env, pat),
+ ) {
+ (Some(ctor), Some(pat)) => ctor.intersection(&pat).map(|_| {
+ let (pat_lo, pat_hi) = pat.range.into_inner();
+ let (ctor_lo, ctor_hi) = ctor.range.into_inner();
+ assert!(pat_lo <= ctor_lo && ctor_hi <= pat_hi);
+ smallvec![]
+ }),
_ => None,
}
} else {
}
}
- PatKind::Array { ref prefix, ref slice, ref suffix } |
- PatKind::Slice { ref prefix, ref slice, ref suffix } => {
- match *constructor {
- Slice(..) => {
- let pat_len = prefix.len() + suffix.len();
- if let Some(slice_count) = wild_patterns.len().checked_sub(pat_len) {
- if slice_count == 0 || slice.is_some() {
- Some(prefix.iter().chain(
- wild_patterns.iter().map(|p| *p)
- .skip(prefix.len())
- .take(slice_count)
- .chain(suffix.iter())
- ).collect())
- } else {
- None
- }
+ PatKind::Array { ref prefix, ref slice, ref suffix }
+ | PatKind::Slice { ref prefix, ref slice, ref suffix } => match *constructor {
+ Slice(..) => {
+ let pat_len = prefix.len() + suffix.len();
+ if let Some(slice_count) = wild_patterns.len().checked_sub(pat_len) {
+ if slice_count == 0 || slice.is_some() {
+ Some(
+ prefix
+ .iter()
+ .chain(
+ wild_patterns
+ .iter()
+ .map(|p| *p)
+ .skip(prefix.len())
+ .take(slice_count)
+ .chain(suffix.iter()),
+ )
+ .collect(),
+ )
} else {
None
}
+ } else {
+ None
}
- ConstantValue(cv, _) => {
- match slice_pat_covered_by_const(
- cx.tcx, pat.span, cv, prefix, slice, suffix, cx.param_env,
- ) {
- Ok(true) => Some(smallvec![]),
- Ok(false) => None,
- Err(ErrorReported) => None
- }
+ }
+ ConstantValue(cv, _) => {
+ match slice_pat_covered_by_const(
+ cx.tcx,
+ pat.span,
+ cv,
+ prefix,
+ slice,
+ suffix,
+ cx.param_env,
+ ) {
+ Ok(true) => Some(smallvec![]),
+ Ok(false) => None,
+ Err(ErrorReported) => None,
}
- _ => span_bug!(pat.span,
- "unexpected ctor {:?} for slice pat", constructor)
}
- }
+ _ => span_bug!(pat.span, "unexpected ctor {:?} for slice pat", constructor),
+ },
PatKind::Or { .. } => {
bug!("support for or-patterns has not been fully implemented yet.");
debug!("specialize({:#?}, {:#?}) = {:#?}", r[0], wild_patterns, head);
head.map(|mut head| {
- head.extend_from_slice(&r[1 ..]);
+ head.extend_from_slice(&r[1..]);
head
})
}
-use super::_match::{MatchCheckCtxt, Matrix, expand_pattern, is_useful};
use super::_match::Usefulness::*;
use super::_match::WitnessPreference::*;
+use super::_match::{expand_pattern, is_useful, MatchCheckCtxt, Matrix};
-use super::{PatCtxt, PatternError, PatKind};
+use super::{PatCtxt, PatKind, PatternError};
+use rustc::lint;
use rustc::session::Session;
-use rustc::ty::{self, Ty, TyCtxt};
use rustc::ty::subst::{InternalSubsts, SubstsRef};
-use rustc::lint;
+use rustc::ty::{self, Ty, TyCtxt};
use rustc_errors::{Applicability, DiagnosticBuilder};
-use rustc::hir::HirId;
use rustc::hir::def::*;
use rustc::hir::def_id::DefId;
-use rustc::hir::intravisit::{self, Visitor, NestedVisitorMap};
+use rustc::hir::intravisit::{self, NestedVisitorMap, Visitor};
+use rustc::hir::HirId;
use rustc::hir::{self, Pat};
use smallvec::smallvec;
use std::slice;
-use syntax_pos::{Span, DUMMY_SP, MultiSpan};
+use syntax_pos::{MultiSpan, Span, DUMMY_SP};
crate fn check_match(tcx: TyCtxt<'_>, def_id: DefId) {
let body_id = match tcx.hir().as_local_hir_id(def_id) {
::rustc::mir::interpret::struct_error(
self.tcx.at(pat_span),
"could not evaluate float literal (see issue #31407)",
- ).emit();
+ )
+ .emit();
}
PatternError::NonConstPath(span) => {
::rustc::mir::interpret::struct_error(
self.tcx.at(span),
"runtime values cannot be referenced in patterns",
- ).emit();
+ )
+ .emit();
}
}
}
check_legality_of_bindings_in_at_patterns(self, pat);
}
- fn check_match(
- &mut self,
- scrut: &hir::Expr,
- arms: &'tcx [hir::Arm],
- source: hir::MatchSource
- ) {
+ fn check_match(&mut self, scrut: &hir::Expr, arms: &'tcx [hir::Arm], source: hir::MatchSource) {
for arm in arms {
// First, check legality of move bindings.
self.check_patterns(arm.guard.is_some(), &arm.pat);
MatchCheckCtxt::create_and_enter(self.tcx, self.param_env, module, |ref mut cx| {
let mut have_errors = false;
- let inlined_arms : Vec<(Vec<_>, _)> = arms.iter().map(|arm| (
- // HACK(or_patterns; Centril | dlrobertson): Remove this and
- // correctly handle exhaustiveness checking for nested or-patterns.
- match &arm.pat.kind {
- hir::PatKind::Or(pats) => pats,
- _ => std::slice::from_ref(&arm.pat),
- }.iter().map(|pat| {
- let mut patcx = PatCtxt::new(
- self.tcx,
- self.param_env.and(self.identity_substs),
- self.tables
- );
- patcx.include_lint_checks();
- let pattern =
- cx.pattern_arena.alloc(expand_pattern(cx, patcx.lower_pattern(&pat))) as &_;
- if !patcx.errors.is_empty() {
- patcx.report_inlining_errors(pat.span);
- have_errors = true;
- }
- (pattern, &**pat)
- }).collect(),
- arm.guard.as_ref().map(|g| match g {
- hir::Guard::If(ref e) => &**e,
+ let inlined_arms: Vec<(Vec<_>, _)> = arms
+ .iter()
+ .map(|arm| {
+ (
+ // HACK(or_patterns; Centril | dlrobertson): Remove this and
+ // correctly handle exhaustiveness checking for nested or-patterns.
+ match &arm.pat.kind {
+ hir::PatKind::Or(pats) => pats,
+ _ => std::slice::from_ref(&arm.pat),
+ }
+ .iter()
+ .map(|pat| {
+ let mut patcx = PatCtxt::new(
+ self.tcx,
+ self.param_env.and(self.identity_substs),
+ self.tables,
+ );
+ patcx.include_lint_checks();
+ let pattern = cx
+ .pattern_arena
+ .alloc(expand_pattern(cx, patcx.lower_pattern(&pat)))
+ as &_;
+ if !patcx.errors.is_empty() {
+ patcx.report_inlining_errors(pat.span);
+ have_errors = true;
+ }
+ (pattern, &**pat)
+ })
+ .collect(),
+ arm.guard.as_ref().map(|g| match g {
+ hir::Guard::If(ref e) => &**e,
+ }),
+ )
})
- )).collect();
+ .collect();
// Bail out early if inlining failed.
if have_errors {
def_span = self.tcx.hir().span_if_local(def.did);
if def.variants.len() < 4 && !def.variants.is_empty() {
// keep around to point at the definition of non-covered variants
- missing_variants = def.variants.iter()
- .map(|variant| variant.ident)
- .collect();
+ missing_variants =
+ def.variants.iter().map(|variant| variant.ident).collect();
}
let is_non_exhaustive_and_non_local =
def.is_variant_list_non_exhaustive() && !def.did.is_local();
!(is_non_exhaustive_and_non_local) && def.variants.is_empty()
- },
- _ => false
+ }
+ _ => false,
}
};
if !scrutinee_is_uninhabited {
let mut err = create_e0004(
self.tcx.sess,
scrut.span,
- format!("non-exhaustive patterns: {}", match missing_variants.len() {
- 0 => format!("type `{}` is non-empty", pat_ty),
- 1 => format!(
- "pattern `{}` of type `{}` is not handled",
- missing_variants[0].name,
- pat_ty,
- ),
- _ => format!("multiple patterns of type `{}` are not handled", pat_ty),
- }),
+ format!(
+ "non-exhaustive patterns: {}",
+ match missing_variants.len() {
+ 0 => format!("type `{}` is non-empty", pat_ty),
+ 1 => format!(
+ "pattern `{}` of type `{}` is not handled",
+ missing_variants[0].name, pat_ty,
+ ),
+ _ => format!(
+ "multiple patterns of type `{}` are not handled",
+ pat_ty
+ ),
+ }
+ ),
+ );
+ err.help(
+ "ensure that all possible cases are being handled, \
+ possibly by adding wildcards or more match arms",
);
- err.help("ensure that all possible cases are being handled, \
- possibly by adding wildcards or more match arms");
if let Some(sp) = def_span {
err.span_label(sp, format!("`{}` defined here", pat_ty));
}
fn check_irrefutable(&self, pat: &'tcx Pat, origin: &str, sp: Option<Span>) {
let module = self.tcx.hir().get_module_parent(pat.hir_id);
MatchCheckCtxt::create_and_enter(self.tcx, self.param_env, module, |ref mut cx| {
- let mut patcx = PatCtxt::new(self.tcx,
- self.param_env.and(self.identity_substs),
- self.tables);
+ let mut patcx =
+ PatCtxt::new(self.tcx, self.param_env.and(self.identity_substs), self.tables);
patcx.include_lint_checks();
let pattern = patcx.lower_pattern(pat);
let pattern_ty = pattern.ty;
let pattern = expand_pattern(cx, pattern);
- let pats: Matrix<'_, '_> = vec![smallvec![
- &pattern
- ]].into_iter().collect();
+ let pats: Matrix<'_, '_> = vec![smallvec![&pattern]].into_iter().collect();
let witnesses = match check_not_useful(cx, pattern_ty, &pats, pat.hir_id) {
Ok(_) => return,
let joined_patterns = joined_uncovered_patterns(&witnesses);
let mut err = struct_span_err!(
- self.tcx.sess, pat.span, E0005,
+ self.tcx.sess,
+ pat.span,
+ E0005,
"refutable pattern in {}: {} not covered",
- origin, joined_patterns
+ origin,
+ joined_patterns
);
let suggest_if_let = match &pat.kind {
hir::PatKind::Path(hir::QPath::Resolved(None, path))
};
if let (Some(span), true) = (sp, suggest_if_let) {
- err.note("`let` bindings require an \"irrefutable pattern\", like a `struct` or \
- an `enum` with only one variant");
+ err.note(
+ "`let` bindings require an \"irrefutable pattern\", like a `struct` or \
+ an `enum` with only one variant",
+ );
if let Ok(snippet) = self.tcx.sess.source_map().span_to_snippet(span) {
err.span_suggestion(
span,
Applicability::HasPlaceholders,
);
}
- err.note("for more information, visit \
- https://doc.rust-lang.org/book/ch18-02-refutability.html");
+ err.note(
+ "for more information, visit \
+ https://doc.rust-lang.org/book/ch18-02-refutability.html",
+ );
}
adt_defined_here(cx, &mut err, pattern_ty, &witnesses);
/// This caused an irrefutable match failure in e.g. `let`.
fn const_not_var(err: &mut DiagnosticBuilder<'_>, tcx: TyCtxt<'_>, pat: &Pat, path: &hir::Path) {
let descr = path.res.descr();
- err.span_label(pat.span, format!(
- "interpreted as {} {} pattern, not a new variable",
- path.res.article(),
- descr,
- ));
+ err.span_label(
+ pat.span,
+ format!("interpreted as {} {} pattern, not a new variable", path.res.article(), descr,),
+ );
err.span_suggestion(
pat.span,
}
let pat_ty = cx.tables.pat_ty(p);
if let ty::Adt(edef, _) = pat_ty.kind {
- if edef.is_enum() && edef.variants.iter().any(|variant| {
- variant.ident == ident && variant.ctor_kind == CtorKind::Const
- }) {
+ if edef.is_enum()
+ && edef.variants.iter().any(|variant| {
+ variant.ident == ident && variant.ctor_kind == CtorKind::Const
+ })
+ {
let ty_path = cx.tcx.def_path_str(edef.did);
- let mut err = struct_span_warn!(cx.tcx.sess, p.span, E0170,
+ let mut err = struct_span_warn!(
+ cx.tcx.sess,
+ p.span,
+ E0170,
"pattern binding `{}` is named the same as one \
- of the variants of the type `{}`",
- ident, ty_path);
+ of the variants of the type `{}`",
+ ident,
+ ty_path
+ );
err.span_suggestion(
p.span,
"to match on the variant, qualify the path",
format!("{}::{}", ty_path, ident),
- Applicability::MachineApplicable
+ Applicability::MachineApplicable,
);
err.emit();
}
hir::PatKind::Binding(.., None) => true,
hir::PatKind::Binding(.., Some(ref s)) => pat_is_catchall(s),
hir::PatKind::Ref(ref s, _) => pat_is_catchall(s),
- hir::PatKind::Tuple(ref v, _) => v.iter().all(|p| {
- pat_is_catchall(&p)
- }),
- _ => false
+ hir::PatKind::Tuple(ref v, _) => v.iter().all(|p| pat_is_catchall(&p)),
+ _ => false,
}
}
match is_useful(cx, &seen, &v, LeaveOutWitness, hir_pat.hir_id) {
NotUseful => {
match source {
- hir::MatchSource::IfDesugar { .. } |
- hir::MatchSource::WhileDesugar => bug!(),
+ hir::MatchSource::IfDesugar { .. } | hir::MatchSource::WhileDesugar => {
+ bug!()
+ }
hir::MatchSource::IfLetDesugar { .. } => {
cx.tcx.lint_hir(
lint::builtin::IRREFUTABLE_LET_PATTERNS,
0 => {
cx.tcx.lint_hir(
lint::builtin::UNREACHABLE_PATTERNS,
- hir_pat.hir_id, pat.span,
- "unreachable pattern");
- },
+ hir_pat.hir_id,
+ pat.span,
+ "unreachable pattern",
+ );
+ }
// The arm with the wildcard pattern.
1 => {
cx.tcx.lint_hir(
pat.span,
"irrefutable while-let pattern",
);
- },
+ }
_ => bug!(),
}
}
- hir::MatchSource::ForLoopDesugar |
- hir::MatchSource::Normal => {
+ hir::MatchSource::ForLoopDesugar | hir::MatchSource::Normal => {
let mut err = cx.tcx.struct_span_lint_hir(
lint::builtin::UNREACHABLE_PATTERNS,
hir_pat.hir_id,
// Unreachable patterns in try and await expressions occur when one of
// the arms are an uninhabited type. Which is OK.
- hir::MatchSource::AwaitDesugar |
- hir::MatchSource::TryDesugar => {}
+ hir::MatchSource::AwaitDesugar | hir::MatchSource::TryDesugar => {}
}
}
Useful => (),
- UsefulWithWitness(_) => bug!()
+ UsefulWithWitness(_) => bug!(),
}
if guard.is_none() {
seen.push(v);
let joined_patterns = joined_uncovered_patterns(&witnesses);
let mut err = create_e0004(
- cx.tcx.sess, sp,
+ cx.tcx.sess,
+ sp,
format!("non-exhaustive patterns: {} not covered", joined_patterns),
);
err.span_label(sp, pattern_not_covered_label(&witnesses, &joined_patterns));
adt_defined_here(cx, &mut err, scrut_ty, &witnesses);
err.help(
"ensure that all possible cases are being handled, \
- possibly by adding wildcards or more match arms"
+ possibly by adding wildcards or more match arms",
)
.emit();
}
// Don't point at variants that have already been covered due to other patterns to avoid
// visual clutter.
for pattern in patterns {
- use PatKind::{AscribeUserType, Deref, Variant, Or, Leaf};
+ use PatKind::{AscribeUserType, Deref, Leaf, Or, Variant};
match &*pattern.kind {
AscribeUserType { subpattern, .. } | Deref { subpattern } => {
covered.extend(maybe_point_at_variant(ty, slice::from_ref(&subpattern)));
}
covered.push(sp);
- let pats = subpatterns.iter()
+ let pats = subpatterns
+ .iter()
.map(|field_pattern| field_pattern.pattern.clone())
.collect::<Box<[_]>>();
covered.extend(maybe_point_at_variant(ty, &pats));
}
Leaf { subpatterns } => {
- let pats = subpatterns.iter()
+ let pats = subpatterns
+ .iter()
.map(|field_pattern| field_pattern.pattern.clone())
.collect::<Box<[_]>>();
covered.extend(maybe_point_at_variant(ty, &pats));
struct AtBindingPatternVisitor<'a, 'b, 'tcx> {
cx: &'a MatchVisitor<'b, 'tcx>,
- bindings_allowed: bool
+ bindings_allowed: bool,
}
impl<'v> Visitor<'v> for AtBindingPatternVisitor<'_, '_, '_> {
match pat.kind {
hir::PatKind::Binding(.., ref subpat) => {
if !self.bindings_allowed {
- struct_span_err!(self.cx.tcx.sess, pat.span, E0303,
- "pattern bindings are not allowed after an `@`")
- .span_label(pat.span, "not allowed after `@`")
- .emit();
+ struct_span_err!(
+ self.cx.tcx.sess,
+ pat.span,
+ E0303,
+ "pattern bindings are not allowed after an `@`"
+ )
+ .span_label(pat.span, "not allowed after `@`")
+ .emit();
}
if subpat.is_some() {
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