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Auto merge of #116734 - Nadrieril:lint-per-column, r=cjgillot

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Lint `non_exhaustive_omitted_patterns` by columns

This is a rework of the `non_exhaustive_omitted_patterns` lint to make it more consistent. The intent of the lint is to help consumers of `non_exhaustive` enums ensure they stay up-to-date with all upstream variants. This rewrite fixes two cases we didn't handle well before:

First, because of details of exhaustiveness checking, the following wouldn't lint `Enum::C` as missing:
```rust
match Some(x) {
    Some(Enum::A) => {}
    Some(Enum::B) => {}
    _ => {}
}
```

Second, because of the fundamental workings of exhaustiveness checking, the following would treat the `true` and `false` cases separately and thus lint about missing variants:
```rust
match (true, x) {
    (true, Enum::A) => {}
    (true, Enum::B) => {}
    (false, Enum::C) => {}
    _ => {}
}
```
Moreover, it would correctly not lint in the case where the pair is flipped, because of asymmetry in how exhaustiveness checking proceeds.

A drawback is that it no longer makes sense to set the lint level per-arm. This will silently break the lint for current users of it (but it's behind a feature gate so that's ok).

The new approach is now independent of the exhaustiveness algorithm; it's a separate pass that looks at patterns column by column. This is another of the motivations for this: I'm glad to move it out of the algorithm, it was akward there.

This PR is almost identical to https://github.com/rust-lang/rust/pull/111651. cc `@eholk` who reviewed it at the time. Compared to then, I'm more confident this is the right approach.
This commit is contained in:
bors 2023-10-21 11:04:19 +00:00
commit 786c94a4eb
11 changed files with 605 additions and 392 deletions
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34
compiler/rustc_lint_defs/src/builtin.rs
View file

@ -3953,8 +3953,13 @@ declare_lint! {
}
declare_lint! {
/// The `non_exhaustive_omitted_patterns` lint detects when a wildcard (`_` or `..`) in a
/// pattern for a `#[non_exhaustive]` struct or enum is reachable.
/// The `non_exhaustive_omitted_patterns` lint aims to help consumers of a `#[non_exhaustive]`
/// struct or enum who want to match all of its fields/variants explicitly.
///
/// The `#[non_exhaustive]` annotation forces matches to use wildcards, so exhaustiveness
/// checking cannot be used to ensure that all fields/variants are matched explicitly. To remedy
/// this, this allow-by-default lint warns the user when a match mentions some but not all of
/// the fields/variants of a `#[non_exhaustive]` struct or enum.
///
/// ### Example
///
@ -3968,9 +3973,9 @@ declare_lint! {
///
/// // in crate B
/// #![feature(non_exhaustive_omitted_patterns_lint)]
/// #[warn(non_exhaustive_omitted_patterns)]
/// match Bar::A {
/// Bar::A => {},
/// #[warn(non_exhaustive_omitted_patterns)]
/// _ => {},
/// }
/// ```
@ -3978,29 +3983,32 @@ declare_lint! {
/// This will produce:
///
/// ```text
/// warning: reachable patterns not covered of non exhaustive enum
/// warning: some variants are not matched explicitly
/// --> $DIR/reachable-patterns.rs:70:9
/// |
/// LL | _ => {}
/// | ^ pattern `B` not covered
/// LL | match Bar::A {
/// | ^ pattern `Bar::B` not covered
/// |
/// note: the lint level is defined here
/// --> $DIR/reachable-patterns.rs:69:16
/// |
/// LL | #[warn(non_exhaustive_omitted_patterns)]
/// | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
/// = help: ensure that all possible cases are being handled by adding the suggested match arms
/// = help: ensure that all variants are matched explicitly by adding the suggested match arms
/// = note: the matched value is of type `Bar` and the `non_exhaustive_omitted_patterns` attribute was found
/// ```
///
/// Warning: setting this to `deny` will make upstream non-breaking changes (adding fields or
/// variants to a `#[non_exhaustive]` struct or enum) break your crate. This goes against
/// expected semver behavior.
///
/// ### Explanation
///
/// Structs and enums tagged with `#[non_exhaustive]` force the user to add a
/// (potentially redundant) wildcard when pattern-matching, to allow for future
/// addition of fields or variants. The `non_exhaustive_omitted_patterns` lint
/// detects when such a wildcard happens to actually catch some fields/variants.
/// In other words, when the match without the wildcard would not be exhaustive.
/// This lets the user be informed if new fields/variants were added.
/// Structs and enums tagged with `#[non_exhaustive]` force the user to add a (potentially
/// redundant) wildcard when pattern-matching, to allow for future addition of fields or
/// variants. The `non_exhaustive_omitted_patterns` lint detects when such a wildcard happens to
/// actually catch some fields/variants. In other words, when the match without the wildcard
/// would not be exhaustive. This lets the user be informed if new fields/variants were added.
pub NON_EXHAUSTIVE_OMITTED_PATTERNS,
Allow,
"detect when patterns of types marked `non_exhaustive` are missed",

4
compiler/rustc_mir_build/src/errors.rs
View file

@ -1,6 +1,6 @@
use crate::{
fluent_generated as fluent,
thir::pattern::{deconstruct_pat::DeconstructedPat, MatchCheckCtxt},
thir::pattern::{deconstruct_pat::WitnessPat, MatchCheckCtxt},
};
use rustc_errors::{
error_code, AddToDiagnostic, Applicability, Diagnostic, DiagnosticBuilder, ErrorGuaranteed,
@ -810,7 +810,7 @@ impl<'tcx> Uncovered<'tcx> {
pub fn new<'p>(
span: Span,
cx: &MatchCheckCtxt<'p, 'tcx>,
witnesses: Vec<DeconstructedPat<'p, 'tcx>>,
witnesses: Vec<WitnessPat<'tcx>>,
) -> Self {
let witness_1 = witnesses.get(0).unwrap().to_pat(cx);
Self {

25
compiler/rustc_mir_build/src/thir/pattern/check_match.rs
View file

@ -1,4 +1,4 @@
use super::deconstruct_pat::{Constructor, DeconstructedPat};
use super::deconstruct_pat::{Constructor, DeconstructedPat, WitnessPat};
use super::usefulness::{
compute_match_usefulness, MatchArm, MatchCheckCtxt, Reachability, UsefulnessReport,
};
@ -279,7 +279,7 @@ impl<'p, 'tcx> MatchVisitor<'_, 'p, 'tcx> {
let scrut = &self.thir[scrut];
let scrut_ty = scrut.ty;
let report = compute_match_usefulness(&cx, &tarms, self.lint_level, scrut_ty);
let report = compute_match_usefulness(&cx, &tarms, self.lint_level, scrut_ty, scrut.span);
match source {
// Don't report arm reachability of desugared `match $iter.into_iter() { iter => .. }`
@ -473,7 +473,8 @@ impl<'p, 'tcx> MatchVisitor<'_, 'p, 'tcx> {
let pattern = self.lower_pattern(&mut cx, pat);
let pattern_ty = pattern.ty();
let arm = MatchArm { pat: pattern, hir_id: self.lint_level, has_guard: false };
let report = compute_match_usefulness(&cx, &[arm], self.lint_level, pattern_ty);
let report =
compute_match_usefulness(&cx, &[arm], self.lint_level, pattern_ty, pattern.span());
// Note: we ignore whether the pattern is unreachable (i.e. whether the type is empty). We
// only care about exhaustiveness here.
@ -662,7 +663,7 @@ fn is_let_irrefutable<'p, 'tcx>(
pat: &'p DeconstructedPat<'p, 'tcx>,
) -> bool {
let arms = [MatchArm { pat, hir_id: pat_id, has_guard: false }];
let report = compute_match_usefulness(&cx, &arms, pat_id, pat.ty());
let report = compute_match_usefulness(&cx, &arms, pat_id, pat.ty(), pat.span());
// Report if the pattern is unreachable, which can only occur when the type is uninhabited.
// This also reports unreachable sub-patterns though, so we can't just replace it with an
@ -701,8 +702,8 @@ fn report_arm_reachability<'p, 'tcx>(
}
}
fn collect_non_exhaustive_tys<'p, 'tcx>(
pat: &DeconstructedPat<'p, 'tcx>,
fn collect_non_exhaustive_tys<'tcx>(
pat: &WitnessPat<'tcx>,
non_exhaustive_tys: &mut FxHashSet<Ty<'tcx>>,
) {
if matches!(pat.ctor(), Constructor::NonExhaustive) {
@ -718,7 +719,7 @@ fn non_exhaustive_match<'p, 'tcx>(
thir: &Thir<'tcx>,
scrut_ty: Ty<'tcx>,
sp: Span,
witnesses: Vec<DeconstructedPat<'p, 'tcx>>,
witnesses: Vec<WitnessPat<'tcx>>,
arms: &[ArmId],
expr_span: Span,
) -> ErrorGuaranteed {
@ -896,10 +897,10 @@ fn non_exhaustive_match<'p, 'tcx>(
pub(crate) fn joined_uncovered_patterns<'p, 'tcx>(
cx: &MatchCheckCtxt<'p, 'tcx>,
witnesses: &[DeconstructedPat<'p, 'tcx>],
witnesses: &[WitnessPat<'tcx>],
) -> String {
const LIMIT: usize = 3;
let pat_to_str = |pat: &DeconstructedPat<'p, 'tcx>| pat.to_pat(cx).to_string();
let pat_to_str = |pat: &WitnessPat<'tcx>| pat.to_pat(cx).to_string();
match witnesses {
[] => bug!(),
[witness] => format!("`{}`", witness.to_pat(cx)),
@ -916,7 +917,7 @@ pub(crate) fn joined_uncovered_patterns<'p, 'tcx>(
}
pub(crate) fn pattern_not_covered_label(
witnesses: &[DeconstructedPat<'_, '_>],
witnesses: &[WitnessPat<'_>],
joined_patterns: &str,
) -> String {
format!("pattern{} {} not covered", rustc_errors::pluralize!(witnesses.len()), joined_patterns)
@ -927,7 +928,7 @@ fn adt_defined_here<'p, 'tcx>(
cx: &MatchCheckCtxt<'p, 'tcx>,
err: &mut Diagnostic,
ty: Ty<'tcx>,
witnesses: &[DeconstructedPat<'p, 'tcx>],
witnesses: &[WitnessPat<'tcx>],
) {
let ty = ty.peel_refs();
if let ty::Adt(def, _) = ty.kind() {
@ -958,7 +959,7 @@ fn adt_defined_here<'p, 'tcx>(
fn maybe_point_at_variant<'a, 'p: 'a, 'tcx: 'a>(
cx: &MatchCheckCtxt<'p, 'tcx>,
def: AdtDef<'tcx>,
patterns: impl Iterator<Item = &'a DeconstructedPat<'p, 'tcx>>,
patterns: impl Iterator<Item = &'a WitnessPat<'tcx>>,
) -> Vec<Span> {
use Constructor::*;
let mut covered = vec![];

282
compiler/rustc_mir_build/src/thir/pattern/deconstruct_pat.rs
View file

@ -629,18 +629,11 @@ pub(super) enum Constructor<'tcx> {
/// `#[doc(hidden)]` ones.
Hidden,
/// Fake extra constructor for constructors that are not seen in the matrix, as explained in the
/// code for [`Constructor::split`]. The carried `bool` is used for the
/// `non_exhaustive_omitted_patterns` lint.
Missing {
nonexhaustive_enum_missing_visible_variants: bool,
},
/// code for [`Constructor::split`].
Missing,
}
impl<'tcx> Constructor<'tcx> {
pub(super) fn is_wildcard(&self) -> bool {
matches!(self, Wildcard)
}
pub(super) fn is_non_exhaustive(&self) -> bool {
matches!(self, NonExhaustive)
}
@ -778,14 +771,8 @@ impl<'tcx> Constructor<'tcx> {
let all_missing = split_set.present.is_empty();
let report_when_all_missing =
pcx.is_top_level && !IntRange::is_integral(pcx.ty);
let ctor = if all_missing && !report_when_all_missing {
Wildcard
} else {
Missing {
nonexhaustive_enum_missing_visible_variants: split_set
.nonexhaustive_enum_missing_visible_variants,
}
};
let ctor =
if all_missing && !report_when_all_missing { Wildcard } else { Missing };
smallvec![ctor]
} else {
split_set.present
@ -905,11 +892,9 @@ pub(super) enum ConstructorSet {
/// either fully included in or disjoint from each constructor in the column. This avoids
/// non-trivial intersections like between `0..10` and `5..15`.
#[derive(Debug)]
struct SplitConstructorSet<'tcx> {
present: SmallVec<[Constructor<'tcx>; 1]>,
missing: Vec<Constructor<'tcx>>,
/// For the `non_exhaustive_omitted_patterns` lint.
nonexhaustive_enum_missing_visible_variants: bool,
pub(super) struct SplitConstructorSet<'tcx> {
pub(super) present: SmallVec<[Constructor<'tcx>; 1]>,
pub(super) missing: Vec<Constructor<'tcx>>,
}
impl ConstructorSet {
@ -1039,7 +1024,7 @@ impl ConstructorSet {
/// constructors to 1/ determine which constructors of the type (if any) are missing; 2/ split
/// constructors to handle non-trivial intersections e.g. on ranges or slices.
#[instrument(level = "debug", skip(self, pcx, ctors), ret)]
fn split<'a, 'tcx>(
pub(super) fn split<'a, 'tcx>(
&self,
pcx: &PatCtxt<'_, '_, 'tcx>,
ctors: impl Iterator<Item = &'a Constructor<'tcx>> + Clone,
@ -1051,7 +1036,6 @@ impl ConstructorSet {
let mut missing = Vec::new();
// Constructors in `ctors`, except wildcards.
let mut seen = ctors.filter(|c| !(matches!(c, Opaque | Wildcard)));
let mut nonexhaustive_enum_missing_visible_variants = false;
match self {
ConstructorSet::Single => {
if seen.next().is_none() {
@ -1063,6 +1047,7 @@ impl ConstructorSet {
ConstructorSet::Variants { visible_variants, hidden_variants, non_exhaustive } => {
let seen_set: FxHashSet<_> = seen.map(|c| c.as_variant().unwrap()).collect();
let mut skipped_a_hidden_variant = false;
for variant in visible_variants {
let ctor = Variant(*variant);
if seen_set.contains(&variant) {
@ -1071,8 +1056,6 @@ impl ConstructorSet {
missing.push(ctor);
}
}
nonexhaustive_enum_missing_visible_variants =
*non_exhaustive && !missing.is_empty();
for variant in hidden_variants {
let ctor = Variant(*variant);
@ -1159,7 +1142,7 @@ impl ConstructorSet {
ConstructorSet::Uninhabited => {}
}
SplitConstructorSet { present, missing, nonexhaustive_enum_missing_visible_variants }
SplitConstructorSet { present, missing }
}
/// Compute the set of constructors missing from this column.
@ -1312,9 +1295,10 @@ impl<'p, 'tcx> Fields<'p, 'tcx> {
/// Values and patterns can be represented as a constructor applied to some fields. This represents
/// a pattern in this form.
/// This also keeps track of whether the pattern has been found reachable during analysis. For this
/// reason we should be careful not to clone patterns for which we care about that. Use
/// `clone_and_forget_reachability` if you're sure.
/// This also uses interior mutability to keep track of whether the pattern has been found reachable
/// during analysis. For this reason they cannot be cloned.
/// A `DeconstructedPat` will almost always come from user input; the only exception are some
/// `Wildcard`s introduced during specialization.
pub(crate) struct DeconstructedPat<'p, 'tcx> {
ctor: Constructor<'tcx>,
fields: Fields<'p, 'tcx>,
@ -1337,20 +1321,6 @@ impl<'p, 'tcx> DeconstructedPat<'p, 'tcx> {
DeconstructedPat { ctor, fields, ty, span, reachable: Cell::new(false) }
}
/// Construct a pattern that matches everything that starts with this constructor.
/// For example, if `ctor` is a `Constructor::Variant` for `Option::Some`, we get the pattern
/// `Some(_)`.
pub(super) fn wild_from_ctor(pcx: &PatCtxt<'_, 'p, 'tcx>, ctor: Constructor<'tcx>) -> Self {
let fields = Fields::wildcards(pcx, &ctor);
DeconstructedPat::new(ctor, fields, pcx.ty, pcx.span)
}
/// Clone this value. This method emphasizes that cloning loses reachability information and
/// should be done carefully.
pub(super) fn clone_and_forget_reachability(&self) -> Self {
DeconstructedPat::new(self.ctor.clone(), self.fields, self.ty, self.span)
}
pub(crate) fn from_pat(cx: &MatchCheckCtxt<'p, 'tcx>, pat: &Pat<'tcx>) -> Self {
let mkpat = |pat| DeconstructedPat::from_pat(cx, pat);
let ctor;
@ -1533,98 +1503,16 @@ impl<'p, 'tcx> DeconstructedPat<'p, 'tcx> {
DeconstructedPat::new(ctor, fields, pat.ty, pat.span)
}
pub(crate) fn to_pat(&self, cx: &MatchCheckCtxt<'p, 'tcx>) -> Pat<'tcx> {
let is_wildcard = |pat: &Pat<'_>| {
matches!(pat.kind, PatKind::Binding { subpattern: None, .. } | PatKind::Wild)
};
let mut subpatterns = self.iter_fields().map(|p| Box::new(p.to_pat(cx)));
let kind = match &self.ctor {
Single | Variant(_) => match self.ty.kind() {
ty::Tuple(..) => PatKind::Leaf {
subpatterns: subpatterns
.enumerate()
.map(|(i, pattern)| FieldPat { field: FieldIdx::new(i), pattern })
.collect(),
},
ty::Adt(adt_def, _) if adt_def.is_box() => {
// Without `box_patterns`, the only legal pattern of type `Box` is `_` (outside
// of `std`). So this branch is only reachable when the feature is enabled and
// the pattern is a box pattern.
PatKind::Deref { subpattern: subpatterns.next().unwrap() }
}
ty::Adt(adt_def, args) => {
let variant_index = self.ctor.variant_index_for_adt(*adt_def);
let variant = &adt_def.variant(variant_index);
let subpatterns = Fields::list_variant_nonhidden_fields(cx, self.ty, variant)
.zip(subpatterns)
.map(|((field, _ty), pattern)| FieldPat { field, pattern })
.collect();
if adt_def.is_enum() {
PatKind::Variant { adt_def: *adt_def, args, variant_index, subpatterns }
} else {
PatKind::Leaf { subpatterns }
}
}
// Note: given the expansion of `&str` patterns done in `expand_pattern`, we should
// be careful to reconstruct the correct constant pattern here. However a string
// literal pattern will never be reported as a non-exhaustiveness witness, so we
// ignore this issue.
ty::Ref(..) => PatKind::Deref { subpattern: subpatterns.next().unwrap() },
_ => bug!("unexpected ctor for type {:?} {:?}", self.ctor, self.ty),
},
Slice(slice) => {
match slice.kind {
FixedLen(_) => PatKind::Slice {
prefix: subpatterns.collect(),
slice: None,
suffix: Box::new([]),
},
VarLen(prefix, _) => {
let mut subpatterns = subpatterns.peekable();
let mut prefix: Vec<_> = subpatterns.by_ref().take(prefix).collect();
if slice.array_len.is_some() {
// Improves diagnostics a bit: if the type is a known-size array, instead
// of reporting `[x, _, .., _, y]`, we prefer to report `[x, .., y]`.
// This is incorrect if the size is not known, since `[_, ..]` captures
// arrays of lengths `>= 1` whereas `[..]` captures any length.
while !prefix.is_empty() && is_wildcard(prefix.last().unwrap()) {
prefix.pop();
}
while subpatterns.peek().is_some()
&& is_wildcard(subpatterns.peek().unwrap())
{
subpatterns.next();
}
}
let suffix: Box<[_]> = subpatterns.collect();
let wild = Pat::wildcard_from_ty(self.ty);
PatKind::Slice {
prefix: prefix.into_boxed_slice(),
slice: Some(Box::new(wild)),
suffix,
}
}
}
}
&Str(value) => PatKind::Constant { value },
IntRange(range) => return range.to_pat(cx.tcx, self.ty),
Wildcard | NonExhaustive | Hidden => PatKind::Wild,
Missing { .. } => bug!(
"trying to convert a `Missing` constructor into a `Pat`; this is probably a bug,
`Missing` should have been processed in `apply_constructors`"
),
F32Range(..) | F64Range(..) | Opaque | Or => {
bug!("can't convert to pattern: {:?}", self)
}
};
Pat { ty: self.ty, span: DUMMY_SP, kind }
}
pub(super) fn is_or_pat(&self) -> bool {
matches!(self.ctor, Or)
}
pub(super) fn flatten_or_pat(&'p self) -> SmallVec<[&'p Self; 1]> {
if self.is_or_pat() {
self.iter_fields().flat_map(|p| p.flatten_or_pat()).collect()
} else {
smallvec![self]
}
}
pub(super) fn ctor(&self) -> &Constructor<'tcx> {
&self.ctor
@ -1804,3 +1692,131 @@ impl<'p, 'tcx> fmt::Debug for DeconstructedPat<'p, 'tcx> {
}
}
}
/// Same idea as `DeconstructedPat`, except this is a fictitious pattern built up for diagnostics
/// purposes. As such they don't use interning and can be cloned.
#[derive(Debug, Clone)]
pub(crate) struct WitnessPat<'tcx> {
ctor: Constructor<'tcx>,
pub(crate) fields: Vec<WitnessPat<'tcx>>,
ty: Ty<'tcx>,
}
impl<'tcx> WitnessPat<'tcx> {
pub(super) fn new(ctor: Constructor<'tcx>, fields: Vec<Self>, ty: Ty<'tcx>) -> Self {
Self { ctor, fields, ty }
}
pub(super) fn wildcard(ty: Ty<'tcx>) -> Self {
Self::new(Wildcard, Vec::new(), ty)
}
/// Construct a pattern that matches everything that starts with this constructor.
/// For example, if `ctor` is a `Constructor::Variant` for `Option::Some`, we get the pattern
/// `Some(_)`.
pub(super) fn wild_from_ctor(pcx: &PatCtxt<'_, '_, 'tcx>, ctor: Constructor<'tcx>) -> Self {
// Reuse `Fields::wildcards` to get the types.
let fields = Fields::wildcards(pcx, &ctor)
.iter_patterns()
.map(|deco_pat| Self::wildcard(deco_pat.ty()))
.collect();
Self::new(ctor, fields, pcx.ty)
}
pub(super) fn ctor(&self) -> &Constructor<'tcx> {
&self.ctor
}
pub(super) fn ty(&self) -> Ty<'tcx> {
self.ty
}
pub(crate) fn to_pat(&self, cx: &MatchCheckCtxt<'_, 'tcx>) -> Pat<'tcx> {
let is_wildcard = |pat: &Pat<'_>| matches!(pat.kind, PatKind::Wild);
let mut subpatterns = self.iter_fields().map(|p| Box::new(p.to_pat(cx)));
let kind = match &self.ctor {
Single | Variant(_) => match self.ty.kind() {
ty::Tuple(..) => PatKind::Leaf {
subpatterns: subpatterns
.enumerate()
.map(|(i, pattern)| FieldPat { field: FieldIdx::new(i), pattern })
.collect(),
},
ty::Adt(adt_def, _) if adt_def.is_box() => {
// Without `box_patterns`, the only legal pattern of type `Box` is `_` (outside
// of `std`). So this branch is only reachable when the feature is enabled and
// the pattern is a box pattern.
PatKind::Deref { subpattern: subpatterns.next().unwrap() }
}
ty::Adt(adt_def, args) => {
let variant_index = self.ctor.variant_index_for_adt(*adt_def);
let variant = &adt_def.variant(variant_index);
let subpatterns = Fields::list_variant_nonhidden_fields(cx, self.ty, variant)
.zip(subpatterns)
.map(|((field, _ty), pattern)| FieldPat { field, pattern })
.collect();
if adt_def.is_enum() {
PatKind::Variant { adt_def: *adt_def, args, variant_index, subpatterns }
} else {
PatKind::Leaf { subpatterns }
}
}
// Note: given the expansion of `&str` patterns done in `expand_pattern`, we should
// be careful to reconstruct the correct constant pattern here. However a string
// literal pattern will never be reported as a non-exhaustiveness witness, so we
// ignore this issue.
ty::Ref(..) => PatKind::Deref { subpattern: subpatterns.next().unwrap() },
_ => bug!("unexpected ctor for type {:?} {:?}", self.ctor, self.ty),
},
Slice(slice) => {
match slice.kind {
FixedLen(_) => PatKind::Slice {
prefix: subpatterns.collect(),
slice: None,
suffix: Box::new([]),
},
VarLen(prefix, _) => {
let mut subpatterns = subpatterns.peekable();
let mut prefix: Vec<_> = subpatterns.by_ref().take(prefix).collect();
if slice.array_len.is_some() {
// Improves diagnostics a bit: if the type is a known-size array, instead
// of reporting `[x, _, .., _, y]`, we prefer to report `[x, .., y]`.
// This is incorrect if the size is not known, since `[_, ..]` captures
// arrays of lengths `>= 1` whereas `[..]` captures any length.
while !prefix.is_empty() && is_wildcard(prefix.last().unwrap()) {
prefix.pop();
}
while subpatterns.peek().is_some()
&& is_wildcard(subpatterns.peek().unwrap())
{
subpatterns.next();
}
}
let suffix: Box<[_]> = subpatterns.collect();
let wild = Pat::wildcard_from_ty(self.ty);
PatKind::Slice {
prefix: prefix.into_boxed_slice(),
slice: Some(Box::new(wild)),
suffix,
}
}
}
}
&Str(value) => PatKind::Constant { value },
IntRange(range) => return range.to_pat(cx.tcx, self.ty),
Wildcard | NonExhaustive | Hidden => PatKind::Wild,
Missing { .. } => bug!(
"trying to convert a `Missing` constructor into a `Pat`; this is probably a bug,
`Missing` should have been processed in `apply_constructors`"
),
F32Range(..) | F64Range(..) | Opaque | Or => {
bug!("can't convert to pattern: {:?}", self)
}
};
Pat { ty: self.ty, span: DUMMY_SP, kind }
}
pub(super) fn iter_fields<'a>(&'a self) -> impl Iterator<Item = &'a WitnessPat<'tcx>> {
self.fields.iter()
}
}

258
compiler/rustc_mir_build/src/thir/pattern/usefulness.rs
View file

@ -213,7 +213,7 @@
//! or-patterns in the first column are expanded before being stored in the matrix. Specialization
//! for a single patstack is done from a combination of [`Constructor::is_covered_by`] and
//! [`PatStack::pop_head_constructor`]. The internals of how it's done mostly live in the
//! [`Fields`] struct.
//! [`super::deconstruct_pat::Fields`] struct.
//!
//!
//! # Computing usefulness
@ -307,7 +307,7 @@
use self::ArmType::*;
use self::Usefulness::*;
use super::deconstruct_pat::{Constructor, ConstructorSet, DeconstructedPat, Fields};
use super::deconstruct_pat::{Constructor, ConstructorSet, DeconstructedPat, WitnessPat};
use crate::errors::{NonExhaustiveOmittedPattern, Uncovered};
use rustc_data_structures::captures::Captures;
@ -322,7 +322,6 @@ use rustc_span::{Span, DUMMY_SP};
use smallvec::{smallvec, SmallVec};
use std::fmt;
use std::iter::once;
pub(crate) struct MatchCheckCtxt<'p, 'tcx> {
pub(crate) tcx: TyCtxt<'tcx>,
@ -555,20 +554,20 @@ impl<'p, 'tcx> fmt::Debug for Matrix<'p, 'tcx> {
/// exhaustiveness of a whole match, we use the `WithWitnesses` variant, which carries a list of
/// witnesses of non-exhaustiveness when there are any.
/// Which variant to use is dictated by `ArmType`.
#[derive(Debug)]
enum Usefulness<'p, 'tcx> {
#[derive(Debug, Clone)]
enum Usefulness<'tcx> {
/// If we don't care about witnesses, simply remember if the pattern was useful.
NoWitnesses { useful: bool },
/// Carries a list of witnesses of non-exhaustiveness. If empty, indicates that the whole
/// pattern is unreachable.
WithWitnesses(Vec<Witness<'p, 'tcx>>),
WithWitnesses(Vec<WitnessStack<'tcx>>),
}
impl<'p, 'tcx> Usefulness<'p, 'tcx> {
impl<'tcx> Usefulness<'tcx> {
fn new_useful(preference: ArmType) -> Self {
match preference {
// A single (empty) witness of reachability.
FakeExtraWildcard => WithWitnesses(vec![Witness(vec![])]),
FakeExtraWildcard => WithWitnesses(vec![WitnessStack(vec![])]),
RealArm => NoWitnesses { useful: true },
}
}
@ -605,8 +604,8 @@ impl<'p, 'tcx> Usefulness<'p, 'tcx> {
/// with the results of specializing with the other constructors.
fn apply_constructor(
self,
pcx: &PatCtxt<'_, 'p, 'tcx>,
matrix: &Matrix<'p, 'tcx>, // used to compute missing ctors
pcx: &PatCtxt<'_, '_, 'tcx>,
matrix: &Matrix<'_, 'tcx>, // used to compute missing ctors
ctor: &Constructor<'tcx>,
) -> Self {
match self {
@ -627,25 +626,18 @@ impl<'p, 'tcx> Usefulness<'p, 'tcx> {
// wildcards for fields, i.e. that matches everything that can be built with it.
// For example, if `ctor` is a `Constructor::Variant` for `Option::Some`, we get
// the pattern `Some(_)`.
let new_patterns: Vec<DeconstructedPat<'_, '_>> = missing
let new_patterns: Vec<WitnessPat<'_>> = missing
.into_iter()
.map(|missing_ctor| {
DeconstructedPat::wild_from_ctor(pcx, missing_ctor.clone())
})
.map(|missing_ctor| WitnessPat::wild_from_ctor(pcx, missing_ctor.clone()))
.collect();
witnesses
.into_iter()
.flat_map(|witness| {
new_patterns.iter().map(move |pat| {
Witness(
witness
.0
.iter()
.chain(once(pat))
.map(DeconstructedPat::clone_and_forget_reachability)
.collect(),
)
let mut stack = witness.clone();
stack.0.push(pat.clone());
stack
})
})
.collect()
@ -667,15 +659,17 @@ enum ArmType {
RealArm,
}
/// A witness of non-exhaustiveness for error reporting, represented
/// as a list of patterns (in reverse order of construction) with
/// wildcards inside to represent elements that can take any inhabitant
/// of the type as a value.
/// A witness-tuple of non-exhaustiveness for error reporting, represented as a list of patterns (in
/// reverse order of construction) with wildcards inside to represent elements that can take any
/// inhabitant of the type as a value.
///
/// A witness against a list of patterns should have the same types
/// and length as the pattern matched against. Because Rust `match`
/// is always against a single pattern, at the end the witness will
/// have length 1, but in the middle of the algorithm, it can contain
/// This mirrors `PatStack`: they function similarly, except `PatStack` contains user patterns we
/// are inspecting, and `WitnessStack` contains witnesses we are constructing.
/// FIXME(Nadrieril): use the same order of patterns for both
///
/// A `WitnessStack` should have the same types and length as the `PatStacks` we are inspecting
/// (except we store the patterns in reverse order). Because Rust `match` is always against a single
/// pattern, at the end the stack will have length 1. In the middle of the algorithm, it can contain
/// multiple patterns.
///
/// For example, if we are constructing a witness for the match against
@ -690,23 +684,37 @@ enum ArmType {
/// # }
/// ```
///
/// We'll perform the following steps:
/// 1. Start with an empty witness
/// `Witness(vec![])`
/// 2. Push a witness `true` against the `false`
/// `Witness(vec![true])`
/// 3. Push a witness `Some(_)` against the `None`
/// `Witness(vec![true, Some(_)])`
/// 4. Apply the `Pair` constructor to the witnesses
/// `Witness(vec![Pair(Some(_), true)])`
/// We'll perform the following steps (among others):
/// - Start with a matrix representing the match
/// `PatStack(vec![Pair(None, _)])`
/// `PatStack(vec![Pair(_, false)])`
/// - Specialize with `Pair`
/// `PatStack(vec![None, _])`
/// `PatStack(vec![_, false])`
/// - Specialize with `Some`
/// `PatStack(vec![_, false])`
/// - Specialize with `_`
/// `PatStack(vec![false])`
/// - Specialize with `true`
/// // no patstacks left
/// - This is a non-exhaustive match: we have the empty witness stack as a witness.
/// `WitnessStack(vec![])`
/// - Apply `true`
/// `WitnessStack(vec![true])`
/// - Apply `_`
/// `WitnessStack(vec![true, _])`
/// - Apply `Some`
/// `WitnessStack(vec![true, Some(_)])`
/// - Apply `Pair`
/// `WitnessStack(vec![Pair(Some(_), true)])`
///
/// The final `Pair(Some(_), true)` is then the resulting witness.
#[derive(Debug)]
pub(crate) struct Witness<'p, 'tcx>(Vec<DeconstructedPat<'p, 'tcx>>);
#[derive(Debug, Clone)]
pub(crate) struct WitnessStack<'tcx>(Vec<WitnessPat<'tcx>>);
impl<'p, 'tcx> Witness<'p, 'tcx> {
impl<'tcx> WitnessStack<'tcx> {
/// Asserts that the witness contains a single pattern, and returns it.
fn single_pattern(self) -> DeconstructedPat<'p, 'tcx> {
fn single_pattern(self) -> WitnessPat<'tcx> {
assert_eq!(self.0.len(), 1);
self.0.into_iter().next().unwrap()
}
@ -724,13 +732,12 @@ impl<'p, 'tcx> Witness<'p, 'tcx> {
///
/// left_ty: struct X { a: (bool, &'static str), b: usize}
/// pats: [(false, "foo"), 42] => X { a: (false, "foo"), b: 42 }
fn apply_constructor(mut self, pcx: &PatCtxt<'_, 'p, 'tcx>, ctor: &Constructor<'tcx>) -> Self {
fn apply_constructor(mut self, pcx: &PatCtxt<'_, '_, 'tcx>, ctor: &Constructor<'tcx>) -> Self {
let pat = {
let len = self.0.len();
let arity = ctor.arity(pcx);
let pats = self.0.drain((len - arity)..).rev();
let fields = Fields::from_iter(pcx.cx, pats);
DeconstructedPat::new(ctor.clone(), fields, pcx.ty, pcx.span)
let fields = self.0.drain((len - arity)..).rev().collect();
WitnessPat::new(ctor.clone(), fields, pcx.ty)
};
self.0.push(pat);
@ -770,7 +777,7 @@ fn is_useful<'p, 'tcx>(
lint_root: HirId,
is_under_guard: bool,
is_top_level: bool,
) -> Usefulness<'p, 'tcx> {
) -> Usefulness<'tcx> {
debug!(?matrix, ?v);
let Matrix { patterns: rows, .. } = matrix;
@ -837,8 +844,6 @@ fn is_useful<'p, 'tcx>(
}
// We split the head constructor of `v`.
let split_ctors = v_ctor.split(pcx, matrix.heads().map(DeconstructedPat::ctor));
let is_non_exhaustive_and_wild =
cx.is_foreign_non_exhaustive_enum(ty) && v_ctor.is_wildcard();
// For each constructor, we compute whether there's a value that starts with it that would
// witness the usefulness of `v`.
let start_matrix = &matrix;
@ -859,50 +864,6 @@ fn is_useful<'p, 'tcx>(
)
});
let usefulness = usefulness.apply_constructor(pcx, start_matrix, &ctor);
// When all the conditions are met we have a match with a `non_exhaustive` enum
// that has the potential to trigger the `non_exhaustive_omitted_patterns` lint.
// To understand the workings checkout `Constructor::split` and `SplitWildcard::new/into_ctors`
if is_non_exhaustive_and_wild
// Only emit a lint on refutable patterns.
&& cx.refutable
// We check that the match has a wildcard pattern and that wildcard is useful,
// meaning there are variants that are covered by the wildcard. Without the check
// for `witness_preference` the lint would trigger on `if let NonExhaustiveEnum::A = foo {}`
&& usefulness.is_useful() && matches!(witness_preference, RealArm)
&& matches!(
&ctor,
Constructor::Missing { nonexhaustive_enum_missing_visible_variants: true }
)
{
let missing = ConstructorSet::for_ty(pcx.cx, pcx.ty)
.compute_missing(pcx, matrix.heads().map(DeconstructedPat::ctor));
// Construct for each missing constructor 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`, we get the pattern `Some(_)`.
let patterns = missing
.into_iter()
// Because of how we computed `nonexhaustive_enum_missing_visible_variants`,
// this will not return an empty `Vec`.
.filter(|c| !(matches!(c, Constructor::NonExhaustive | Constructor::Hidden)))
.map(|missing_ctor| DeconstructedPat::wild_from_ctor(pcx, missing_ctor))
.collect::<Vec<_>>();
// Report that a match of a `non_exhaustive` enum marked with `non_exhaustive_omitted_patterns`
// is not exhaustive enough.
//
// NB: The partner lint for structs lives in `compiler/rustc_hir_analysis/src/check/pat.rs`.
cx.tcx.emit_spanned_lint(
NON_EXHAUSTIVE_OMITTED_PATTERNS,
lint_root,
pcx.span,
NonExhaustiveOmittedPattern {
scrut_ty: pcx.ty,
uncovered: Uncovered::new(pcx.span, pcx.cx, patterns),
},
);
}
ret.extend(usefulness);
}
}
@ -914,6 +875,80 @@ fn is_useful<'p, 'tcx>(
ret
}
/// Traverse the patterns to collect any variants of a non_exhaustive enum that fail to be mentioned
/// in a given column. This traverses patterns column-by-column, where a column is the intuitive
/// notion of "subpatterns that inspect the same subvalue".
/// Despite similarities with `is_useful`, this traversal is different. Notably this is linear in the
/// depth of patterns, whereas `is_useful` is worst-case exponential (exhaustiveness is NP-complete).
fn collect_nonexhaustive_missing_variants<'p, 'tcx>(
cx: &MatchCheckCtxt<'p, 'tcx>,
column: &[&DeconstructedPat<'p, 'tcx>],
) -> Vec<WitnessPat<'tcx>> {
let ty = column[0].ty();
let pcx = &PatCtxt { cx, ty, span: DUMMY_SP, is_top_level: false };
let set = ConstructorSet::for_ty(pcx.cx, pcx.ty).split(pcx, column.iter().map(|p| p.ctor()));
if set.present.is_empty() {
// We can't consistently handle the case where no constructors are present (since this would
// require digging deep through any type in case there's a non_exhaustive enum somewhere),
// so for consistency we refuse to handle the top-level case, where we could handle it.
return vec![];
}
let mut witnesses = Vec::new();
if cx.is_foreign_non_exhaustive_enum(ty) {
witnesses.extend(
set.missing
.into_iter()
// This will list missing visible variants.
.filter(|c| !matches!(c, Constructor::Hidden | Constructor::NonExhaustive))
.map(|missing_ctor| WitnessPat::wild_from_ctor(pcx, missing_ctor)),
)
}
// Recurse into the fields.
for ctor in set.present {
let arity = ctor.arity(pcx);
if arity == 0 {
continue;
}
// We specialize the column by `ctor`. This gives us `arity`-many columns of patterns. These
// columns may have different lengths in the presence of or-patterns (this is why we can't
// reuse `Matrix`).
let mut specialized_columns: Vec<Vec<_>> = (0..arity).map(|_| Vec::new()).collect();
let relevant_patterns = column.iter().filter(|pat| ctor.is_covered_by(pcx, pat.ctor()));
for pat in relevant_patterns {
let specialized = pat.specialize(pcx, &ctor);
for (subpat, sub_column) in specialized.iter().zip(&mut specialized_columns) {
if subpat.is_or_pat() {
sub_column.extend(subpat.iter_fields())
} else {
sub_column.push(subpat)
}
}
}
debug_assert!(
!specialized_columns[0].is_empty(),
"ctor {ctor:?} was listed as present but isn't"
);
let wild_pat = WitnessPat::wild_from_ctor(pcx, ctor);
for (i, col_i) in specialized_columns.iter().enumerate() {
// Compute witnesses for each column.
let wits_for_col_i = collect_nonexhaustive_missing_variants(cx, col_i.as_slice());
// For each witness, we build a new pattern in the shape of `ctor(_, _, wit, _, _)`,
// adding enough wildcards to match `arity`.
for wit in wits_for_col_i {
let mut pat = wild_pat.clone();
pat.fields[i] = wit;
witnesses.push(pat);
}
}
}
witnesses
}
/// The arm of a match expression.
#[derive(Clone, Copy, Debug)]
pub(crate) struct MatchArm<'p, 'tcx> {
@ -940,7 +975,7 @@ pub(crate) struct UsefulnessReport<'p, 'tcx> {
pub(crate) arm_usefulness: Vec<(MatchArm<'p, 'tcx>, Reachability)>,
/// If the match is exhaustive, this is empty. If not, this contains witnesses for the lack of
/// exhaustiveness.
pub(crate) non_exhaustiveness_witnesses: Vec<DeconstructedPat<'p, 'tcx>>,
pub(crate) non_exhaustiveness_witnesses: Vec<WitnessPat<'tcx>>,
}
/// The entrypoint for the usefulness algorithm. Computes whether a match is exhaustive and which
@ -954,6 +989,7 @@ pub(crate) fn compute_match_usefulness<'p, 'tcx>(
arms: &[MatchArm<'p, 'tcx>],
lint_root: HirId,
scrut_ty: Ty<'tcx>,
scrut_span: Span,
) -> UsefulnessReport<'p, 'tcx> {
let mut matrix = Matrix::empty();
let arm_usefulness: Vec<_> = arms
@ -978,9 +1014,39 @@ pub(crate) fn compute_match_usefulness<'p, 'tcx>(
let wild_pattern = cx.pattern_arena.alloc(DeconstructedPat::wildcard(scrut_ty, DUMMY_SP));
let v = PatStack::from_pattern(wild_pattern);
let usefulness = is_useful(cx, &matrix, &v, FakeExtraWildcard, lint_root, false, true);
let non_exhaustiveness_witnesses = match usefulness {
let non_exhaustiveness_witnesses: Vec<_> = match usefulness {
WithWitnesses(pats) => pats.into_iter().map(|w| w.single_pattern()).collect(),
NoWitnesses { .. } => bug!(),
};
// Run the non_exhaustive_omitted_patterns lint. Only run on refutable patterns to avoid hitting
// `if let`s. Only run if the match is exhaustive otherwise the error is redundant.
if cx.refutable
&& non_exhaustiveness_witnesses.is_empty()
&& !matches!(
cx.tcx.lint_level_at_node(NON_EXHAUSTIVE_OMITTED_PATTERNS, lint_root).0,
rustc_session::lint::Level::Allow
)
{
let pat_column = arms.iter().flat_map(|arm| arm.pat.flatten_or_pat()).collect::<Vec<_>>();
let witnesses = collect_nonexhaustive_missing_variants(cx, &pat_column);
if !witnesses.is_empty() {
// Report that a match of a `non_exhaustive` enum marked with `non_exhaustive_omitted_patterns`
// is not exhaustive enough.
//
// NB: The partner lint for structs lives in `compiler/rustc_hir_analysis/src/check/pat.rs`.
cx.tcx.emit_spanned_lint(
NON_EXHAUSTIVE_OMITTED_PATTERNS,
lint_root,
scrut_span,
NonExhaustiveOmittedPattern {
scrut_ty,
uncovered: Uncovered::new(scrut_span, cx, witnesses),
},
);
}
}
UsefulnessReport { arm_usefulness, non_exhaustiveness_witnesses }
}

18
tests/ui/feature-gates/feature-gate-non_exhaustive_omitted_patterns_lint.rs
View file

@ -3,13 +3,17 @@
#![deny(non_exhaustive_omitted_patterns)]
//~^ WARNING unknown lint: `non_exhaustive_omitted_patterns`
//~| WARNING unknown lint: `non_exhaustive_omitted_patterns`
//~| WARNING unknown lint: `non_exhaustive_omitted_patterns`
#![allow(non_exhaustive_omitted_patterns)]
//~^ WARNING unknown lint: `non_exhaustive_omitted_patterns`
//~| WARNING unknown lint: `non_exhaustive_omitted_patterns`
//~| WARNING unknown lint: `non_exhaustive_omitted_patterns`
fn main() {
enum Foo {
A, B, C,
A,
B,
C,
}
#[allow(non_exhaustive_omitted_patterns)]
@ -17,18 +21,22 @@ fn main() {
//~| WARNING unknown lint: `non_exhaustive_omitted_patterns`
//~| WARNING unknown lint: `non_exhaustive_omitted_patterns`
//~| WARNING unknown lint: `non_exhaustive_omitted_patterns`
//~| WARNING unknown lint: `non_exhaustive_omitted_patterns`
match Foo::A {
//~^ ERROR non-exhaustive patterns: `Foo::C` not covered
Foo::A => {}
Foo::B => {}
}
//~^^^^ ERROR non-exhaustive patterns: `Foo::C` not covered
#[warn(non_exhaustive_omitted_patterns)]
//~^ WARNING unknown lint: `non_exhaustive_omitted_patterns`
//~| WARNING unknown lint: `non_exhaustive_omitted_patterns`
//~| WARNING unknown lint: `non_exhaustive_omitted_patterns`
//~| WARNING unknown lint: `non_exhaustive_omitted_patterns`
//~| WARNING unknown lint: `non_exhaustive_omitted_patterns`
match Foo::A {
Foo::A => {}
Foo::B => {}
#[warn(non_exhaustive_omitted_patterns)]
_ => {}
}
//~^^^ WARNING unknown lint: `non_exhaustive_omitted_patterns`
//~| WARNING unknown lint: `non_exhaustive_omitted_patterns`
}

101
tests/ui/feature-gates/feature-gate-non_exhaustive_omitted_patterns_lint.stderr
View file

@ -10,7 +10,7 @@ LL | #![deny(non_exhaustive_omitted_patterns)]
= note: `#[warn(unknown_lints)]` on by default
warning: unknown lint: `non_exhaustive_omitted_patterns`
--> $DIR/feature-gate-non_exhaustive_omitted_patterns_lint.rs:6:1
--> $DIR/feature-gate-non_exhaustive_omitted_patterns_lint.rs:7:1
|
LL | #![allow(non_exhaustive_omitted_patterns)]
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@ -20,7 +20,7 @@ LL | #![allow(non_exhaustive_omitted_patterns)]
= help: add `#![feature(non_exhaustive_omitted_patterns_lint)]` to the crate attributes to enable
warning: unknown lint: `non_exhaustive_omitted_patterns`
--> $DIR/feature-gate-non_exhaustive_omitted_patterns_lint.rs:15:5
--> $DIR/feature-gate-non_exhaustive_omitted_patterns_lint.rs:19:5
|
LL | #[allow(non_exhaustive_omitted_patterns)]
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@ -30,7 +30,7 @@ LL | #[allow(non_exhaustive_omitted_patterns)]
= help: add `#![feature(non_exhaustive_omitted_patterns_lint)]` to the crate attributes to enable
warning: unknown lint: `non_exhaustive_omitted_patterns`
--> $DIR/feature-gate-non_exhaustive_omitted_patterns_lint.rs:15:5
--> $DIR/feature-gate-non_exhaustive_omitted_patterns_lint.rs:19:5
|
LL | #[allow(non_exhaustive_omitted_patterns)]
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@ -41,15 +41,26 @@ LL | #[allow(non_exhaustive_omitted_patterns)]
= note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
warning: unknown lint: `non_exhaustive_omitted_patterns`
--> $DIR/feature-gate-non_exhaustive_omitted_patterns_lint.rs:29:9
--> $DIR/feature-gate-non_exhaustive_omitted_patterns_lint.rs:31:5
|
LL | #[warn(non_exhaustive_omitted_patterns)]
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
LL | #[warn(non_exhaustive_omitted_patterns)]
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= note: the `non_exhaustive_omitted_patterns` lint is unstable
= note: see issue #89554 <https://github.com/rust-lang/rust/issues/89554> for more information
= help: add `#![feature(non_exhaustive_omitted_patterns_lint)]` to the crate attributes to enable
warning: unknown lint: `non_exhaustive_omitted_patterns`
--> $DIR/feature-gate-non_exhaustive_omitted_patterns_lint.rs:31:5
|
LL | #[warn(non_exhaustive_omitted_patterns)]
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= note: the `non_exhaustive_omitted_patterns` lint is unstable
= note: see issue #89554 <https://github.com/rust-lang/rust/issues/89554> for more information
= help: add `#![feature(non_exhaustive_omitted_patterns_lint)]` to the crate attributes to enable
= note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
warning: unknown lint: `non_exhaustive_omitted_patterns`
--> $DIR/feature-gate-non_exhaustive_omitted_patterns_lint.rs:3:1
|
@ -62,7 +73,7 @@ LL | #![deny(non_exhaustive_omitted_patterns)]
= note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
warning: unknown lint: `non_exhaustive_omitted_patterns`
--> $DIR/feature-gate-non_exhaustive_omitted_patterns_lint.rs:6:1
--> $DIR/feature-gate-non_exhaustive_omitted_patterns_lint.rs:7:1
|
LL | #![allow(non_exhaustive_omitted_patterns)]
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@ -73,7 +84,7 @@ LL | #![allow(non_exhaustive_omitted_patterns)]
= note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
warning: unknown lint: `non_exhaustive_omitted_patterns`
--> $DIR/feature-gate-non_exhaustive_omitted_patterns_lint.rs:15:5
--> $DIR/feature-gate-non_exhaustive_omitted_patterns_lint.rs:19:5
|
LL | #[allow(non_exhaustive_omitted_patterns)]
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@ -84,7 +95,7 @@ LL | #[allow(non_exhaustive_omitted_patterns)]
= note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
warning: unknown lint: `non_exhaustive_omitted_patterns`
--> $DIR/feature-gate-non_exhaustive_omitted_patterns_lint.rs:15:5
--> $DIR/feature-gate-non_exhaustive_omitted_patterns_lint.rs:19:5
|
LL | #[allow(non_exhaustive_omitted_patterns)]
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@ -95,10 +106,21 @@ LL | #[allow(non_exhaustive_omitted_patterns)]
= note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
warning: unknown lint: `non_exhaustive_omitted_patterns`
--> $DIR/feature-gate-non_exhaustive_omitted_patterns_lint.rs:29:9
--> $DIR/feature-gate-non_exhaustive_omitted_patterns_lint.rs:31:5
|
LL | #[warn(non_exhaustive_omitted_patterns)]
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
LL | #[warn(non_exhaustive_omitted_patterns)]
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= note: the `non_exhaustive_omitted_patterns` lint is unstable
= note: see issue #89554 <https://github.com/rust-lang/rust/issues/89554> for more information
= help: add `#![feature(non_exhaustive_omitted_patterns_lint)]` to the crate attributes to enable
= note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
warning: unknown lint: `non_exhaustive_omitted_patterns`
--> $DIR/feature-gate-non_exhaustive_omitted_patterns_lint.rs:31:5
|
LL | #[warn(non_exhaustive_omitted_patterns)]
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= note: the `non_exhaustive_omitted_patterns` lint is unstable
= note: see issue #89554 <https://github.com/rust-lang/rust/issues/89554> for more information
@ -106,18 +128,19 @@ LL | #[warn(non_exhaustive_omitted_patterns)]
= note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
error[E0004]: non-exhaustive patterns: `Foo::C` not covered
--> $DIR/feature-gate-non_exhaustive_omitted_patterns_lint.rs:20:11
--> $DIR/feature-gate-non_exhaustive_omitted_patterns_lint.rs:25:11
|
LL | match Foo::A {
| ^^^^^^ pattern `Foo::C` not covered
|
note: `Foo` defined here
--> $DIR/feature-gate-non_exhaustive_omitted_patterns_lint.rs:12:15
--> $DIR/feature-gate-non_exhaustive_omitted_patterns_lint.rs:16:9
|
LL | enum Foo {
| ---
LL | A, B, C,
| ^ not covered
...
LL | C,
| ^ not covered
= note: the matched value is of type `Foo`
help: ensure that all possible cases are being handled by adding a match arm with a wildcard pattern or an explicit pattern as shown
|
@ -125,6 +148,50 @@ LL ~ Foo::B => {},
LL + Foo::C => todo!()
|
error: aborting due to previous error; 10 warnings emitted
warning: unknown lint: `non_exhaustive_omitted_patterns`
--> $DIR/feature-gate-non_exhaustive_omitted_patterns_lint.rs:3:1
|
LL | #![deny(non_exhaustive_omitted_patterns)]
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= note: the `non_exhaustive_omitted_patterns` lint is unstable
= note: see issue #89554 <https://github.com/rust-lang/rust/issues/89554> for more information
= help: add `#![feature(non_exhaustive_omitted_patterns_lint)]` to the crate attributes to enable
= note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
warning: unknown lint: `non_exhaustive_omitted_patterns`
--> $DIR/feature-gate-non_exhaustive_omitted_patterns_lint.rs:7:1
|
LL | #![allow(non_exhaustive_omitted_patterns)]
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= note: the `non_exhaustive_omitted_patterns` lint is unstable
= note: see issue #89554 <https://github.com/rust-lang/rust/issues/89554> for more information
= help: add `#![feature(non_exhaustive_omitted_patterns_lint)]` to the crate attributes to enable
= note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
warning: unknown lint: `non_exhaustive_omitted_patterns`
--> $DIR/feature-gate-non_exhaustive_omitted_patterns_lint.rs:19:5
|
LL | #[allow(non_exhaustive_omitted_patterns)]
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= note: the `non_exhaustive_omitted_patterns` lint is unstable
= note: see issue #89554 <https://github.com/rust-lang/rust/issues/89554> for more information
= help: add `#![feature(non_exhaustive_omitted_patterns_lint)]` to the crate attributes to enable
= note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
warning: unknown lint: `non_exhaustive_omitted_patterns`
--> $DIR/feature-gate-non_exhaustive_omitted_patterns_lint.rs:31:5
|
LL | #[warn(non_exhaustive_omitted_patterns)]
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= note: the `non_exhaustive_omitted_patterns` lint is unstable
= note: see issue #89554 <https://github.com/rust-lang/rust/issues/89554> for more information
= help: add `#![feature(non_exhaustive_omitted_patterns_lint)]` to the crate attributes to enable
= note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
error: aborting due to previous error; 16 warnings emitted
For more information about this error, try `rustc --explain E0004`.

78
tests/ui/rfcs/rfc-2008-non-exhaustive/omitted-patterns.rs
View file

@ -13,8 +13,8 @@ use enums::{
EmptyNonExhaustiveEnum, NestedNonExhaustive, NonExhaustiveEnum, NonExhaustiveSingleVariant,
VariantNonExhaustive,
};
use unstable::{UnstableEnum, OnlyUnstableEnum, UnstableStruct, OnlyUnstableStruct};
use structs::{FunctionalRecord, MixedVisFields, NestedStruct, NormalStruct};
use unstable::{OnlyUnstableEnum, OnlyUnstableStruct, UnstableEnum, UnstableStruct};
#[non_exhaustive]
#[derive(Default)]
@ -35,10 +35,10 @@ fn main() {
let enumeration = Bar::A;
// Ok: this is a crate local non_exhaustive enum
#[deny(non_exhaustive_omitted_patterns)]
match enumeration {
Bar::A => {}
Bar::B => {}
#[deny(non_exhaustive_omitted_patterns)]
_ => {}
}
@ -51,50 +51,87 @@ fn main() {
_ => {}
}
#[deny(non_exhaustive_omitted_patterns)]
match non_enum {
//~^ some variants are not matched explicitly
NonExhaustiveEnum::Unit => {}
NonExhaustiveEnum::Tuple(_) => {}
#[deny(non_exhaustive_omitted_patterns)]
_ => {}
}
//~^^ some variants are not matched explicitly
#[deny(non_exhaustive_omitted_patterns)]
match non_enum {
//~^ some variants are not matched explicitly
NonExhaustiveEnum::Unit | NonExhaustiveEnum::Struct { .. } => {}
#[deny(non_exhaustive_omitted_patterns)]
_ => {}
}
//~^^ some variants are not matched explicitly
let x = 5;
// We ignore the guard.
#[deny(non_exhaustive_omitted_patterns)]
match non_enum {
NonExhaustiveEnum::Unit if x > 10 => {}
NonExhaustiveEnum::Tuple(_) => {}
NonExhaustiveEnum::Struct { .. } => {}
#[deny(non_exhaustive_omitted_patterns)]
_ => {}
}
//~^^ some variants are not matched explicitly
#[deny(non_exhaustive_omitted_patterns)]
match (non_enum, true) {
(NonExhaustiveEnum::Unit, true) => {}
(NonExhaustiveEnum::Tuple(_), false) => {}
(NonExhaustiveEnum::Struct { .. }, false) => {}
_ => {}
}
#[deny(non_exhaustive_omitted_patterns)]
match (non_enum, true) {
//~^ some variants are not matched explicitly
(NonExhaustiveEnum::Unit, true) => {}
(NonExhaustiveEnum::Tuple(_), false) => {}
_ => {}
}
#[deny(non_exhaustive_omitted_patterns)]
match (true, non_enum) {
(true, NonExhaustiveEnum::Unit) => {}
(false, NonExhaustiveEnum::Tuple(_)) => {}
(false, NonExhaustiveEnum::Struct { .. }) => {}
_ => {}
}
#[deny(non_exhaustive_omitted_patterns)]
match (true, non_enum) {
//~^ some variants are not matched explicitly
(true, NonExhaustiveEnum::Unit) => {}
(false, NonExhaustiveEnum::Tuple(_)) => {}
_ => {}
}
#[deny(non_exhaustive_omitted_patterns)]
match Some(non_enum) {
//~^ some variants are not matched explicitly
Some(NonExhaustiveEnum::Unit) => {}
Some(NonExhaustiveEnum::Tuple(_)) => {}
_ => {}
}
// Ok: all covered and not `unreachable-patterns`
#[deny(unreachable_patterns)]
#[deny(non_exhaustive_omitted_patterns)]
match non_enum {
NonExhaustiveEnum::Unit => {}
NonExhaustiveEnum::Tuple(_) => {}
NonExhaustiveEnum::Struct { .. } => {}
#[deny(non_exhaustive_omitted_patterns)]
_ => {}
}
#[deny(non_exhaustive_omitted_patterns)]
match NestedNonExhaustive::B {
//~^ some variants are not matched explicitly
NestedNonExhaustive::A(NonExhaustiveEnum::Unit) => {}
NestedNonExhaustive::A(_) => {}
NestedNonExhaustive::B => {}
_ => {}
}
//~^^ some variants are not matched explicitly
//~^^^^^ some variants are not matched explicitly
#[warn(non_exhaustive_omitted_patterns)]
match VariantNonExhaustive::Baz(1, 2) {
@ -120,30 +157,36 @@ fn main() {
#[warn(non_exhaustive_omitted_patterns)]
let MixedVisFields { a, b, .. } = MixedVisFields::default();
// Ok: because this only has 1 variant
// Ok: this only has 1 variant
#[deny(non_exhaustive_omitted_patterns)]
match NonExhaustiveSingleVariant::A(true) {
NonExhaustiveSingleVariant::A(true) => {}
_ => {}
}
// We can't catch the case below, so for consistency we don't catch this one either.
#[deny(non_exhaustive_omitted_patterns)]
match NonExhaustiveSingleVariant::A(true) {
_ => {}
}
//~^^ some variants are not matched explicitly
// We can't catch this case, because this would require digging fully through all the values of
// any type we encounter. We need to be able to only consider present constructors.
#[deny(non_exhaustive_omitted_patterns)]
match &NonExhaustiveSingleVariant::A(true) {
_ => {}
}
// Ok: we don't lint on `if let` expressions
#[deny(non_exhaustive_omitted_patterns)]
if let NonExhaustiveEnum::Tuple(_) = non_enum {}
#[deny(non_exhaustive_omitted_patterns)]
match UnstableEnum::Stable {
//~^ some variants are not matched explicitly
UnstableEnum::Stable => {}
UnstableEnum::Stable2 => {}
#[deny(non_exhaustive_omitted_patterns)]
_ => {}
}
//~^^ some variants are not matched explicitly
// Ok: the feature is on and all variants are matched
#[deny(non_exhaustive_omitted_patterns)]
@ -164,10 +207,10 @@ fn main() {
#[deny(non_exhaustive_omitted_patterns)]
match OnlyUnstableEnum::Unstable {
//~^ some variants are not matched explicitly
OnlyUnstableEnum::Unstable => {}
_ => {}
}
//~^^ some variants are not matched explicitly
#[warn(non_exhaustive_omitted_patterns)]
let OnlyUnstableStruct { unstable, .. } = OnlyUnstableStruct::new();
@ -194,14 +237,13 @@ fn main() {
let local_refutable @ NonExhaustiveEnum::Unit = NonExhaustiveEnum::Unit;
//~^ refutable pattern in local binding
// Check that matching on a reference results in a correctly spanned diagnostic
#[deny(non_exhaustive_omitted_patterns)]
match &non_enum {
//~^ some variants are not matched explicitly
NonExhaustiveEnum::Unit => {}
NonExhaustiveEnum::Tuple(_) => {}
_ => {}
}
//~^^ some variants are not matched explicitly
}
#[deny(non_exhaustive_omitted_patterns)]

177
tests/ui/rfcs/rfc-2008-non-exhaustive/omitted-patterns.stderr
View file

@ -1,5 +1,5 @@
warning: some fields are not explicitly listed
--> $DIR/omitted-patterns.rs:102:9
--> $DIR/omitted-patterns.rs:139:9
|
LL | VariantNonExhaustive::Bar { x, .. } => {}
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ field `y` not listed
@ -7,13 +7,13 @@ LL | VariantNonExhaustive::Bar { x, .. } => {}
= help: ensure that all fields are mentioned explicitly by adding the suggested fields
= note: the pattern is of type `VariantNonExhaustive` and the `non_exhaustive_omitted_patterns` attribute was found
note: the lint level is defined here
--> $DIR/omitted-patterns.rs:99:12
--> $DIR/omitted-patterns.rs:136:12
|
LL | #[warn(non_exhaustive_omitted_patterns)]
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
warning: some fields are not explicitly listed
--> $DIR/omitted-patterns.rs:107:9
--> $DIR/omitted-patterns.rs:144:9
|
LL | let FunctionalRecord { first_field, second_field, .. } = FunctionalRecord::default();
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ field `third_field` not listed
@ -21,13 +21,13 @@ LL | let FunctionalRecord { first_field, second_field, .. } = FunctionalReco
= help: ensure that all fields are mentioned explicitly by adding the suggested fields
= note: the pattern is of type `FunctionalRecord` and the `non_exhaustive_omitted_patterns` attribute was found
note: the lint level is defined here
--> $DIR/omitted-patterns.rs:106:12
--> $DIR/omitted-patterns.rs:143:12
|
LL | #[warn(non_exhaustive_omitted_patterns)]
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
warning: some fields are not explicitly listed
--> $DIR/omitted-patterns.rs:115:29
--> $DIR/omitted-patterns.rs:152:29
|
LL | let NestedStruct { bar: NormalStruct { first_field, .. }, .. } = NestedStruct::default();
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ field `second_field` not listed
@ -35,13 +35,13 @@ LL | let NestedStruct { bar: NormalStruct { first_field, .. }, .. } = Nested
= help: ensure that all fields are mentioned explicitly by adding the suggested fields
= note: the pattern is of type `NormalStruct` and the `non_exhaustive_omitted_patterns` attribute was found
note: the lint level is defined here
--> $DIR/omitted-patterns.rs:114:12
--> $DIR/omitted-patterns.rs:151:12
|
LL | #[warn(non_exhaustive_omitted_patterns)]
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
warning: some fields are not explicitly listed
--> $DIR/omitted-patterns.rs:115:9
--> $DIR/omitted-patterns.rs:152:9
|
LL | let NestedStruct { bar: NormalStruct { first_field, .. }, .. } = NestedStruct::default();
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ field `foo` not listed
@ -50,7 +50,7 @@ LL | let NestedStruct { bar: NormalStruct { first_field, .. }, .. } = Nested
= note: the pattern is of type `NestedStruct` and the `non_exhaustive_omitted_patterns` attribute was found
warning: some fields are not explicitly listed
--> $DIR/omitted-patterns.rs:173:9
--> $DIR/omitted-patterns.rs:216:9
|
LL | let OnlyUnstableStruct { unstable, .. } = OnlyUnstableStruct::new();
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ field `unstable2` not listed
@ -58,13 +58,13 @@ LL | let OnlyUnstableStruct { unstable, .. } = OnlyUnstableStruct::new();
= help: ensure that all fields are mentioned explicitly by adding the suggested fields
= note: the pattern is of type `OnlyUnstableStruct` and the `non_exhaustive_omitted_patterns` attribute was found
note: the lint level is defined here
--> $DIR/omitted-patterns.rs:172:12
--> $DIR/omitted-patterns.rs:215:12
|
LL | #[warn(non_exhaustive_omitted_patterns)]
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
warning: some fields are not explicitly listed
--> $DIR/omitted-patterns.rs:181:9
--> $DIR/omitted-patterns.rs:224:9
|
LL | let UnstableStruct { stable, stable2, .. } = UnstableStruct::default();
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ field `unstable` not listed
@ -72,120 +72,125 @@ LL | let UnstableStruct { stable, stable2, .. } = UnstableStruct::default();
= help: ensure that all fields are mentioned explicitly by adding the suggested fields
= note: the pattern is of type `UnstableStruct` and the `non_exhaustive_omitted_patterns` attribute was found
note: the lint level is defined here
--> $DIR/omitted-patterns.rs:180:12
--> $DIR/omitted-patterns.rs:223:12
|
LL | #[warn(non_exhaustive_omitted_patterns)]
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
error: some variants are not matched explicitly
--> $DIR/omitted-patterns.rs:58:9
--> $DIR/omitted-patterns.rs:55:11
|
LL | _ => {}
| ^ pattern `NonExhaustiveEnum::Struct { .. }` not covered
LL | match non_enum {
| ^^^^^^^^ pattern `NonExhaustiveEnum::Struct { .. }` not covered
|
= help: ensure that all variants are matched explicitly by adding the suggested match arms
= note: the matched value is of type `NonExhaustiveEnum` and the `non_exhaustive_omitted_patterns` attribute was found
note: the lint level is defined here
--> $DIR/omitted-patterns.rs:57:16
|
LL | #[deny(non_exhaustive_omitted_patterns)]
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
error: some variants are not matched explicitly
--> $DIR/omitted-patterns.rs:65:9
|
LL | _ => {}
| ^ pattern `NonExhaustiveEnum::Tuple(_)` not covered
|
= help: ensure that all variants are matched explicitly by adding the suggested match arms
= note: the matched value is of type `NonExhaustiveEnum` and the `non_exhaustive_omitted_patterns` attribute was found
note: the lint level is defined here
--> $DIR/omitted-patterns.rs:64:16
|
LL | #[deny(non_exhaustive_omitted_patterns)]
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
error: some variants are not matched explicitly
--> $DIR/omitted-patterns.rs:75:9
|
LL | _ => {}
| ^ pattern `NonExhaustiveEnum::Unit` not covered
|
= help: ensure that all variants are matched explicitly by adding the suggested match arms
= note: the matched value is of type `NonExhaustiveEnum` and the `non_exhaustive_omitted_patterns` attribute was found
note: the lint level is defined here
--> $DIR/omitted-patterns.rs:74:16
|
LL | #[deny(non_exhaustive_omitted_patterns)]
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
error: some variants are not matched explicitly
--> $DIR/omitted-patterns.rs:92:32
|
LL | NestedNonExhaustive::A(_) => {}
| ^ patterns `NonExhaustiveEnum::Tuple(_)` and `NonExhaustiveEnum::Struct { .. }` not covered
|
= help: ensure that all variants are matched explicitly by adding the suggested match arms
= note: the matched value is of type `NonExhaustiveEnum` and the `non_exhaustive_omitted_patterns` attribute was found
note: the lint level is defined here
--> $DIR/omitted-patterns.rs:89:12
--> $DIR/omitted-patterns.rs:54:12
|
LL | #[deny(non_exhaustive_omitted_patterns)]
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
error: some variants are not matched explicitly
--> $DIR/omitted-patterns.rs:94:9
--> $DIR/omitted-patterns.rs:63:11
|
LL | _ => {}
| ^ pattern `NestedNonExhaustive::C` not covered
LL | match non_enum {
| ^^^^^^^^ pattern `NonExhaustiveEnum::Tuple(_)` not covered
|
= help: ensure that all variants are matched explicitly by adding the suggested match arms
= note: the matched value is of type `NonExhaustiveEnum` and the `non_exhaustive_omitted_patterns` attribute was found
note: the lint level is defined here
--> $DIR/omitted-patterns.rs:62:12
|
LL | #[deny(non_exhaustive_omitted_patterns)]
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
error: some variants are not matched explicitly
--> $DIR/omitted-patterns.rs:87:11
|
LL | match (non_enum, true) {
| ^^^^^^^^^^^^^^^^ pattern `(NonExhaustiveEnum::Struct { .. }, _)` not covered
|
= help: ensure that all variants are matched explicitly by adding the suggested match arms
= note: the matched value is of type `(NonExhaustiveEnum, bool)` and the `non_exhaustive_omitted_patterns` attribute was found
note: the lint level is defined here
--> $DIR/omitted-patterns.rs:86:12
|
LL | #[deny(non_exhaustive_omitted_patterns)]
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
error: some variants are not matched explicitly
--> $DIR/omitted-patterns.rs:102:11
|
LL | match (true, non_enum) {
| ^^^^^^^^^^^^^^^^ pattern `(_, NonExhaustiveEnum::Struct { .. })` not covered
|
= help: ensure that all variants are matched explicitly by adding the suggested match arms
= note: the matched value is of type `(bool, NonExhaustiveEnum)` and the `non_exhaustive_omitted_patterns` attribute was found
note: the lint level is defined here
--> $DIR/omitted-patterns.rs:101:12
|
LL | #[deny(non_exhaustive_omitted_patterns)]
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
error: some variants are not matched explicitly
--> $DIR/omitted-patterns.rs:110:11
|
LL | match Some(non_enum) {
| ^^^^^^^^^^^^^^ pattern `Some(NonExhaustiveEnum::Struct { .. })` not covered
|
= help: ensure that all variants are matched explicitly by adding the suggested match arms
= note: the matched value is of type `Option<NonExhaustiveEnum>` and the `non_exhaustive_omitted_patterns` attribute was found
note: the lint level is defined here
--> $DIR/omitted-patterns.rs:109:12
|
LL | #[deny(non_exhaustive_omitted_patterns)]
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
error: some variants are not matched explicitly
--> $DIR/omitted-patterns.rs:128:11
|
LL | match NestedNonExhaustive::B {
| ^^^^^^^^^^^^^^^^^^^^^^ patterns `NestedNonExhaustive::C`, `NestedNonExhaustive::A(NonExhaustiveEnum::Tuple(_))` and `NestedNonExhaustive::A(NonExhaustiveEnum::Struct { .. })` not covered
|
= help: ensure that all variants are matched explicitly by adding the suggested match arms
= note: the matched value is of type `NestedNonExhaustive` and the `non_exhaustive_omitted_patterns` attribute was found
error: some variants are not matched explicitly
--> $DIR/omitted-patterns.rs:132:9
|
LL | _ => {}
| ^ pattern `NonExhaustiveSingleVariant::A(_)` not covered
|
= help: ensure that all variants are matched explicitly by adding the suggested match arms
= note: the matched value is of type `NonExhaustiveSingleVariant` and the `non_exhaustive_omitted_patterns` attribute was found
note: the lint level is defined here
--> $DIR/omitted-patterns.rs:130:12
--> $DIR/omitted-patterns.rs:127:12
|
LL | #[deny(non_exhaustive_omitted_patterns)]
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
error: some variants are not matched explicitly
--> $DIR/omitted-patterns.rs:144:9
--> $DIR/omitted-patterns.rs:184:11
|
LL | _ => {}
| ^ pattern `UnstableEnum::Unstable` not covered
LL | match UnstableEnum::Stable {
| ^^^^^^^^^^^^^^^^^^^^ pattern `UnstableEnum::Unstable` not covered
|
= help: ensure that all variants are matched explicitly by adding the suggested match arms
= note: the matched value is of type `UnstableEnum` and the `non_exhaustive_omitted_patterns` attribute was found
note: the lint level is defined here
--> $DIR/omitted-patterns.rs:143:16
--> $DIR/omitted-patterns.rs:183:12
|
LL | #[deny(non_exhaustive_omitted_patterns)]
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
LL | #[deny(non_exhaustive_omitted_patterns)]
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
error: some variants are not matched explicitly
--> $DIR/omitted-patterns.rs:168:9
--> $DIR/omitted-patterns.rs:209:11
|
LL | _ => {}
| ^ pattern `OnlyUnstableEnum::Unstable2` not covered
LL | match OnlyUnstableEnum::Unstable {
| ^^^^^^^^^^^^^^^^^^^^^^^^^^ pattern `OnlyUnstableEnum::Unstable2` not covered
|
= help: ensure that all variants are matched explicitly by adding the suggested match arms
= note: the matched value is of type `OnlyUnstableEnum` and the `non_exhaustive_omitted_patterns` attribute was found
note: the lint level is defined here
--> $DIR/omitted-patterns.rs:165:12
--> $DIR/omitted-patterns.rs:208:12
|
LL | #[deny(non_exhaustive_omitted_patterns)]
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
error[E0005]: refutable pattern in local binding
--> $DIR/omitted-patterns.rs:194:9
--> $DIR/omitted-patterns.rs:237:9
|
LL | let local_refutable @ NonExhaustiveEnum::Unit = NonExhaustiveEnum::Unit;
| ^^^^^^^^^^^^^^^ pattern `_` not covered
@ -199,15 +204,15 @@ LL | let local_refutable @ NonExhaustiveEnum::Unit = NonExhaustiveEnum::Unit
| ++++++++++++++++
error: some variants are not matched explicitly
--> $DIR/omitted-patterns.rs:202:9
--> $DIR/omitted-patterns.rs:241:11
|
LL | _ => {}
| ^ pattern `NonExhaustiveEnum::Struct { .. }` not covered
LL | match &non_enum {
| ^^^^^^^^^ pattern `&NonExhaustiveEnum::Struct { .. }` not covered
|
= help: ensure that all variants are matched explicitly by adding the suggested match arms
= note: the matched value is of type `NonExhaustiveEnum` and the `non_exhaustive_omitted_patterns` attribute was found
= note: the matched value is of type `&NonExhaustiveEnum` and the `non_exhaustive_omitted_patterns` attribute was found
note: the lint level is defined here
--> $DIR/omitted-patterns.rs:198:12
--> $DIR/omitted-patterns.rs:240:12
|
LL | #[deny(non_exhaustive_omitted_patterns)]
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

8
tests/ui/rfcs/rfc-2008-non-exhaustive/stable-omitted-patterns.rs
View file

@ -6,23 +6,23 @@
// aux-build:unstable.rs
extern crate unstable;
use unstable::{UnstableEnum, OnlyUnstableEnum, UnstableStruct, OnlyUnstableStruct};
use unstable::{OnlyUnstableEnum, OnlyUnstableStruct, UnstableEnum, UnstableStruct};
fn main() {
// OK: this matches all the stable variants
#[deny(non_exhaustive_omitted_patterns)]
match UnstableEnum::Stable {
UnstableEnum::Stable => {}
UnstableEnum::Stable2 => {}
#[deny(non_exhaustive_omitted_patterns)]
_ => {}
}
#[deny(non_exhaustive_omitted_patterns)]
match UnstableEnum::Stable {
//~^ some variants are not matched explicitly
UnstableEnum::Stable => {}
#[deny(non_exhaustive_omitted_patterns)]
_ => {}
}
//~^^ some variants are not matched explicitly
// Ok: although this is a bit odd, we don't have anything to report
// since there is no stable variants and the feature is off

12
tests/ui/rfcs/rfc-2008-non-exhaustive/stable-omitted-patterns.stderr
View file

@ -13,18 +13,18 @@ LL | #[warn(non_exhaustive_omitted_patterns)]
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
error: some variants are not matched explicitly
--> $DIR/stable-omitted-patterns.rs:23:9
--> $DIR/stable-omitted-patterns.rs:21:11
|
LL | _ => {}
| ^ pattern `UnstableEnum::Stable2` not covered
LL | match UnstableEnum::Stable {
| ^^^^^^^^^^^^^^^^^^^^ pattern `UnstableEnum::Stable2` not covered
|
= help: ensure that all variants are matched explicitly by adding the suggested match arms
= note: the matched value is of type `UnstableEnum` and the `non_exhaustive_omitted_patterns` attribute was found
note: the lint level is defined here
--> $DIR/stable-omitted-patterns.rs:22:16
--> $DIR/stable-omitted-patterns.rs:20:12
|
LL | #[deny(non_exhaustive_omitted_patterns)]
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
LL | #[deny(non_exhaustive_omitted_patterns)]
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
error: aborting due to previous error; 1 warning emitted