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Gracefully abort on type incompatibility

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Since the only use of `TypeCx::bug` is in `Constructor::is_covered_by`,
it is tempting to return `false` instead of `Err()`, but that would
cause "non-exhaustive match" false positives.
This commit is contained in:
Nadrieril
2024-01-24 16:24:52 +01:00
parent 11f32b73e0
commit 400dc46a05
5 changed files with 18 additions and 14 deletions
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18
compiler/rustc_pattern_analysis/src/constructor.rs
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@@ -826,10 +826,12 @@ impl<Cx: TypeCx> Constructor<Cx> {
/// this checks for inclusion.
// We inline because this has a single call site in `Matrix::specialize_constructor`.
#[inline]
pub(crate) fn is_covered_by(&self, cx: &Cx, other: &Self) -> bool {
match (self, other) {
pub(crate) fn is_covered_by(&self, cx: &Cx, other: &Self) -> Result<bool, Cx::Error> {
Ok(match (self, other) {
(Wildcard, _) => {
cx.bug(format_args!("Constructor splitting should not have returned `Wildcard`"))
return Err(cx.bug(format_args!(
"Constructor splitting should not have returned `Wildcard`"
)));
}
// Wildcards cover anything
(_, Wildcard) => true,
@@ -871,10 +873,12 @@ impl<Cx: TypeCx> Constructor<Cx> {
(Opaque(self_id), Opaque(other_id)) => self_id == other_id,
(Opaque(..), _) | (_, Opaque(..)) => false,
_ => cx.bug(format_args!(
"trying to compare incompatible constructors {self:?} and {other:?}"
)),
}
_ => {
return Err(cx.bug(format_args!(
"trying to compare incompatible constructors {self:?} and {other:?}"
)));
}
})
}
}